PEPTIDE-BASED SYSTEMS FOR DELIVERY OF COSMETIC AGENTS CROSS REFERENCE TO RELATED APPLICATIONS This application claims the benefit of U.S. Provisional Application No. 61/164,533, filed March 30,2009, the entirety of which is incorporated herein. TECHNICAL FIELD The present invention relates to compositions and systems comprising peptide-based reagents for delivery of cosmetic benefit agents to human hair, human skin, and/or human nail. BACKGROUND Many cosmetic care products are comprised of one or more particulate benefit agents, for example, coloring agents and conditioning agents that improve the cosmetic properties of keratin-containing body surfaces such as hair, skin, and nails. These particulate benefit agents do not durably bind to these body surfaces. As a result, these products need to be frequently reapplied to the body surface in order to maintain the desired effect. Various protein-based reagents have been developed in attempts to improve the binding durability of the benefit agent for a target surface or for targeted delivery of a benefit agent to a target surface. Overall, these are impractical and many of these "binding" proteins are expensive and difficult to prepare and include, for example, immunoglobulins, immunoglobulin-derived proteins, and non-immunoglobulin binding proteins that require a complex support scaffold for effective binding (See Binz, H. et al. (2005) Nature Biotechnology 23,1257-1268 for a review of various scaffold-assisted approaches). Single chain peptides and peptide-based reagents have been reported for use in cosmetic applications, for example, traditional colorants and conditioners for hair, skin, and nails (Huang et al. in U.S. Patent 7,220,405 and U.S. Patent Application Publication Nos. US2005/0226839, US2007/0053837, and US2008/0152600; Wang etal. in U.S. Patent Application Publication Nos. US2007/0196395 and US2006/0199206; O'Brien et al. in U.S. Patent Application Publication No. US2006/0073111, U.S. Patent No. 7,285264 and Published PCT Application No. WO2008/054746; Beck et al. in U.S. Patent Application Publication No. US2007/0065387; Fahnestock et al. in U.S. Patent Application Publication No. US2008/0107614; and Benson et al. in U.S. Patent Application Nos. 12/198358 and 12/198382), carbon nanotube-based hair colorants (Huang et al. in U.S. Patent Application Publication No. US2005/0229335), skin sunscreen agents (Buseman-Williams et al. in U.S. Patent 7,309,482 and Lowe et al. in U.S. Patent Application Publication No. US2007/0110686), hair sunscreen agents (Beck et al. in U.S. Patent Application Publication No. 2008/0175798), antidandruff agents (O'Brien et al in U.S. Patent Application No. 12/273,753), and antiacne agents (O'Brien et al. in U.S. Patent Application No. 12/273,778). Certain single chain binding peptides with strong affinity for hair, skin, and/or nails have been identified using phage display (Huang et al., supra; Estell et al. in Published PCT Application No. WOO 1/79479; Murray et al. in U.S. Patent Application Publication No. 2002/0098524; Janssen et al., U.S. Patent Application Publication No. 2003/0152976; and Janssen et al. in Published PCT Application No.WO04/048399). Additionally, empirically-generated hair and skin-binding peptides that are based on positively charged amino acids have been reported (WO 2004/000257 to Rothe et al.). These approaches illustrate that short, linear peptides lacking complex scaffolds and/or immunoglobulin-like structures can have strong affinity (i.e., Kd < 10-5 M) for the surface of hair, skin, and/or nails. The binding strength, however, of a single, short peptide may not be sufficient to meet the durability required for most cosmetic applications. In those applications, two or more of the identified surface-binding peptides can be linked together to prepare linear binding domains (also referred to herein as "hands") having an increased affinity for the targeted surface {i.e., skin, hair, or nails). Often, two or more binding domains may be linked via short peptide spacers separating the individual target surface-binding peptides. Peptides having multiple, rationally-designed binding domains have been reported wherein each domain was designed to couple together at least two substrates, wherein at least one of the binding domains was designed to have affinity for at least one keratin-containing body substrate (e.g., hair, skin, and/or nails) while the second binding domain was designed to have affinity for a benefit agent (U.S. Published Patent Application No. US2007/0065387 to Beck et al. and U.S. Patent 7,285,264 to O'Brien et al.; and U.S. Patent Application Publication No. 2003/0185870 to Grinstaff et al.). These peptide-based reagents comprise at least two binding domains (referred to herein as "two-handed peptides" or "two-handed peptide-based reagents"), wherein each binding domain has been designed to have an affinity for their respective substrate There remains a need for selective linear peptides and cosmetic systems that can effectively couple a benefit agent to human hair, skin, and/or nails and that are not "two-handed." There also remains a need for selective peptides wherein the benefit agent can be unbound from the peptide using mild conditions. SUMMARY The present invention is directed to cosmetic systems comprising a peptidic component comprising at least one binding domain which binds to at least one of human hair, human skin or human nail with a Kd or MB50 value of 10'5 molar or less and which further comprises the first part of an affinity pair; and a stable dispersion of particulate benefit agent having average particle size of between about 0.01 micron and about 75 microns and the second part of the affinity pair; the at least one binding domain has a greater binding affinity for the human hair, skin or nail than it has for the particles of the dispersion. Methods of using the cosmetic systems of the invention are also described, including the application of a benefit agent and the removal of the benefit agent from at least one of human hair, skin or nail. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 depicts the fluorescence of one embodiment of the invention, biotinylated HCP5 dimer peptide, bound the particles to hair. FIG. 2 is a histogram demonstrating hair coloring ability of certain embodiments of the invention using silica-coated iron oxide pigment. FIG. 3A depicts hair tresses treated with according to the procedures set forth in Example 7 after initial exposure to coated iron oxide particles. FIG. 3B depicts hair tresses treated according to the procedures set forth in Example 7, followed by washing with water. FIG. 3C depicts hair tresses treated according to the procedures set forth in Example 7, followed by washing with 0.25% SLES Wash. FIG. 4A is an electron micrograph of a hair treated with (HCP5)2-biotin and 500 nm streptavidin-coated iron oxide particles. FIG. 4B is an electron micrograph of a hair treated with (HCP5)2-biotin and 200 nm streptavidin-coated iron oxide particle. SEQUENCE DESCRIPTIONS The following sequences conform with 37 C.F.R. 1.821 -1.825 ("Requirements for Patent Applications Containing Nucleotide Sequences and/or Amino Acid Sequence Disclosures - the Sequence Rules") and consistent with World Intellectual Property Organization (WIPO) Standard ST.25 (1998) and the sequence listing requirements of the EPO and PCT (Rules 5.2 and 49.5(a-bis), and Section 208 and Annex C of the Administrative Instructions). The symbols and format used for nucleotide and amino acid sequence data comply with the rules set forth in 37 C.F.R. §1.822. SEQ ID NOs: 1-184 and 186-189 are amino acid sequences of keratin-containing body surface-binding peptides. SEQ ID NOs: 1-134 and 184 are amino acid sequences of hair-binding peptides. SEQ ID NOs: 130-134 are empirically-generated sequences that bind to hair and skin. SEQ ID NOs: 135-182 are amino acid sequences of skin-binding peptides. SEQ ID NOs: 183-184 are amino acid sequences to nail-binding peptides. SEQ ID NO: 185 is the amino acid sequence of peptide ("HAT") tag that binds to metal ions. SEQ ID NO: 186 is the amino acid sequence of SEQ ID NO: 76 with a C-terminal lysine residue. SEQ ID NO: 187 is the amino acid sequence of SEQ ID NO: 82 with a C-terminal lysine residue. SEQ ID NO: 188 is the amino acid sequence of SEQ ID NO: 86 with a C-terminal lysine residue. SEQ ID NO: 189 is the amino acid sequence of SEQ ID NO: 110 with a C-terminal lysine residue. SEQ ID NO: 190 is the amino acid sequence of a peptide comprising a randomized version of SEQ ID NO: 82. SEQ ID NO: 191 is the amino acid sequence of a peptide comprising a randomized version of SEQ ID NO: 120. SEQ ID NO: 192 is the amino acid sequence of a peptide comprising a randomized version of SEQ ID NO: 30. SEQ ID NO: 193 is the amino acid sequence of a pigment binding peptide. SEQ ID NO: 194 is the amino acid sequence of a cellulose acetate binding peptide. SEQ ID NO: 195 is the amino acid sequence of a cellulose acetate binding peptide. SEQ ID NO: 196 is the amino acid sequence of peptide HC263. SEQ ID NO: 197 is the amino acid sequence of peptide HC264. SEQ ID NO: 198 is the amino acid sequence of peptide HC214. SEQ ID NO: 199 is the amino acid sequence of peptide HC204. SEQ ID NO: 200 is the amino acid sequence of peptide HC205. SEQ ID NO: 201 is the amino acid sequence of peptide HC352. SEQ ID NO: 202 is the amino acid sequence of peptide HC423. SEQ ID NO: 203 is the amino acid sequence of peptide HC424. SEQ ID NO: 204 is the amino acid sequence of peptide (HCP5)2 also referred to herein as "HCP5-dimer". SEQ ID NO: 205 is the amino acid sequence of peptide of SEQ ID NO: 204 with a C-terminal lysine. SEQ ID NO: 206 is the amino acid sequence of a streptavidin-binding peptide tag. SEQ ID NO: 207 is the amino acid sequence of peptide HC260. SEQ ID NO: 208 is the amino acid sequence of the peptide linker "tonB". SEQ ID NO: 209 is the amino acid sequence of a peptide bridge. SEQ ID NO: 210 is the amino acid sequence of peptide HC353. SEQ ID NO: 211 is the amino acid sequence of peptide HC634. SEQ ID NO: 212 is the amino acid sequence of peptide HC635. SEQ ID NO: 213 is the amino acid sequence of peptide HC636. SEQ ID NO: 214 is the amino acid sequence of peptide HC637. SEQ ID NO: 215 is the amino acid sequence of peptide HC638. SEQ ID NO: 216 is the amino acid sequence of peptide HC639. SEQ ID NO: 217 is the amino acid sequence of peptide HC640. SEQ ID NO: 218 is the amino acid sequence of peptide HC641. SEQ ID NO: 219 is the amino acid sequence of peptide HC642. SEQ ID NO: 220 is the amino acid sequence of peptide HC643. SEQ ID NO: 221 is the amino acid sequence of peptide HC644. SEQ ID NO: 222 is the amino acid sequence of peptide HC645. SEQ ID NOs: 223-234 are amino acid sequences of peptides designed to electrostatically associate with a pigment surface. SEQ ID No: 235 is the amino acid sequence of peptide HHHHHH. SEQ ID NO: 225 is the amino acid sequence of SEQ ID NO: 212 with a C-terminal polylysine block. DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS Improved cosmetic systems for applying a benefit agent to at least one of human hair, human skin, or human nail have been developed and are described herein. Methods of preparing and using these systems are also described. The cosmetic systems of the present invention comprise a peptidic component and a particulate benefit agent provided in a stable particulate dispersion. The Peptidic Component The peptidic component comprises at least one peptidic binding domain that binds to at least one human body surface that is human hair, human skin, or human nail. Certain peptidic components of the invention will be about 500 amino acids, or less, in length. The peptidic component can be provided as, for example, an aqueous solution, a powder, an emulsion, a suspension, a dispersion, a gel, a cream, or an aerosol. The peptidic component may be applied to at least one of human hair, skin, or nail at a concentration of about 0.01% to about 10%, in some embodiments, about 0.01% to about 5%, by weight of the total composition. Within the scope of the invention, the terms "peptide," "peptidic," and "polypeptide" will be used interchangeably to refer to a polymer of two or more amino acids joined together by a peptide bond, wherein the peptide is of unspecified length. Peptides, oligopeptides, and polypeptides are included within the present definition. In one aspect, this term also includes post expression modifications of the peptide, for example, glycosylations, acetylations, phosphorylations, and the like. Also included within the definition are, for example, peptides containing one or more analogues of an amino acid or labeled amino acids and peptidomimetics. In exemplary embodiments, the peptidic component will comprise 15 to 500,15 to 250, or 15 to 100 amino acids. The following abbreviations will be used to identify specific amino acids. Amino Acid 3-Letter 1-Letter Abbreviation Abbreviation Alanine Ala A Arginine Arg R Asparagine Asn N Aspartic acid Asp D Cysteine Cys C Glutamine Gin Q Glutamic acid Glu E Glycine Gly G Histidine His H Isoleucine He I Leucine Leu L Lysine Lys K Methionine Met M Phenylalanine Phe F Proline Pro P Serine Ser S Amino Acid 3-Letter 1-Letter Abbreviation Abbreviation Threonine Thr T Tryptophan Trp W Tyrosine Tyr Y Valine Val V Any amino acid (or as defined herein) Xaa X As used herein, "binding domain" refers to a peptide comprising one, ideally two or more shorter peptides ("subdomains") that have been identified as having an affinity for a particular surface or surfaces, for example, human hair, skin, and/or nails. In certain embodiments, a binding domain may include from 2 to about 50 or 2 to about 25, of the shorter peptides. Other embodiments include those having binding domains including 2 to about 10 shorter peptides. Other embodiments are those binding domains including 2,3,4, or 5 shorter peptides. These shorter peptides may be directly linked to each other to form a binding domain or may be linked via one or more short peptide spacers to form a binding domain. In some embodiments, peptide spacers are from 1 to 100 or 1 to 50, amino acids in length. In other embodiments, the peptide spacers are about 1 to about 25, 3 to about 40, or 3 to about 30 amino acids in length. In still other embodiments are spacers that are about 5 to about 20 amino acids in length. In certain embodiments, the binding domain of the invention binds to at least one of human hair, skin, and nail with a binding affinity value of 10s molar (M) or less. In some embodiments, the peptidic binding domains will have a binding affinity value of 10"5 or less in the presence of at least about 50 - 500 mM salt. The term "binding affinity" refers to the strength of the interaction of a binding peptide with its respective substrate, in this case, human hair, skin, or nail. Binding affinity can be defined or measured in terms of the binding peptide's dissociation constant ("Kd"), or "MB50." "Kd" corresponds to the concentration of peptide at which the binding site on the target is half occupied, i.e., when the concentration of target with peptide bound (bound target material) equals the concentration of target with no peptide bound. The smaller the dissociation constant, the more tightly the peptide is bound. For example, a peptide with a nanomolar (nM) dissociation constant binds more tightly than a peptide with a micromolar (µM) dissociation constant. Certain embodiments of the invention will have a Kd value of 10-5 or less. "MB50" refers to the concentration of the binding peptide that gives a signal that is 50% of the maximum signal obtained in an ELISA-based binding assay. See, e.g., Example 3 of U.S. Patent Application Publication 2005/022683; hereby incorporated by reference. The MB50 provides an indication of the strength of the binding interaction or affinity of the components of the complex. The lower the value of MB50, the stronger, i.e., "better," the interaction of the peptide with its corresponding substrate. For example, a peptide with a nanomolar (nM) MB30 binds more tightly than a peptide with a micromolar (uM) MB50. Certain embodiments of the invention will have a MB50 value of 10"5 or less. In some embodiments, the peptidic binding domains have a binding affinity, as measured by Kd or MB50 values, of less than or equal to about 10-5 M, less than or equal to about 10-6 M, less than or equal to about 10-7 M, less than or equal to about 10-8 M, less than or equal to about 10-9 M, or less than or equal to about 10-10 M. Peptides that have been identified to bind to at least human hair are also referred to as "hair-binding peptides (HBP)." Peptides that have been identified to bind to at least human skin are also referred to as "skin-binding peptides (SBP)." Peptides that have been identified to bind to at least human nail are also referred to as "nail-binding peptides (NBP)." In some embodiments, peptidic binding domains are comprised of peptidic binding subdomains that are up to about 60 amino acids in length. Certain embodiment will have peptidic bind subdomains that are 7 to about 60 amino acids in length. In other embodiments are those peptidic binding subdomains that are 7 to 50 or 7 to 30 amino acids in length. In still other embodiments are those peptidic binding subdomains that are 7 to 27 amino acids in length. While peptidic components comprising a single hair-, skin-, and/or nail-binding domain are certain embodiments of the invention, in other embodiments of the invention, it may be advantageous that the peptidic component comprise more than one binding domain that binds to at least one of human hair, human skin, or human nail. The inclusion of multiple, i.e„ two or more, binding domains can provide a peptidic component that is, for example, even more cosmetically durable than those peptidic components including a single binding domain. In some embodiments, the peptidic component includes from 2 to about 50 or 2 to about 25 peptidic binding domains. Other embodiments include those peptidic components including 2 to about 10 or 2 to 5 peptidic binding domains. The multiple binding domains can be linked directly together or they can be linked together using peptide spacers. Certain peptide spacers are from 1 to 100 or 1 to 50 amino acids in length. In some embodiments, the peptide spacers are about 1 to about 25, 3 to about 40, or 3 to about 30 amino acids in length. In other embodiments are spacers that are about 5 to about 20 amino acids in length. The binding domains of the invention will also have a greater binding affinity for the human hair, skin, or nail than they have for the particles of the dispersion. This preferential affinity of the binding domains for the human hair, skin, or nail over the particles of the dispersion results in a cosmetic system wherein a greater percentage of the binding domains are available for binding to the at least one of human hair skin or nail as compared to those systems wherein the binding domains do not have a greater binding affinity for the human hair, skin or nail over the particles of the dispersion. In some embodiments, the binding domains have at least about a 2-fold greater (i.e., about 2 times greater) binding affinity for the human hair, skin, or nail than they have for the particles of the dispersion. In other embodiments, the binding domains have at least a 5-fold greater (i.e, about 5-times greater) binding affinity for the human hair, skin, or nail than they have for the particles of the dispersion. In still other embodiments, the binding domains have at least a 10-fold greater (i.e, about 10-times greater) binding affinity for the human hair, skin, or nail than they have for the particles of the dispersion. Peptidic binding domains, and the shorter peptides of which they are comprised, can be identified using any number of methods known to those skilled in the art, including, for example, any known biopanning techniques such as phage display, bacterial display, yeast display, ribosome display, mKNA display, and combinations thereof. The generation of random libraries of peptides is well known and may be accomplished by a variety of techniques including, bacterial display (Kemp, D.J.; Proc. Natl. Acad. Sci. USA 78(7):4520-4524 (1981), and Helfman et al., Proc. Natl. Acad. Sci. USA 80(l):31-35, (1983)), yeast display (Chien et al., Proc Natl Acad Sci USA 88(21):9578-82 (1991)), combinatorial solid phase peptide synthesis (U.S. Patent No. 5,449,754, U.S. Patent No. 5,480,971, U.S. Patent No. 5,585,275, U.S. Patent No.5,639,603), and phage display technology (U.S. Patent No. 5,223,409, U.S. Patent No. 5,403,484, U.S. Patent No. 5,571,698, U.S. Patent No. 5,837,500); ribosome display (U.S. Patent No. 5,643,768; U.S. Patent No. 5,658,754; and U.S. Patent No. 7,074,557), and mRNA display technology (PROFUSION™; U.S. Patent No. 6,258,558; U.S. Patent No. 6,518,018; U.S. Patent No. 6,281,344; U.S. Patent No. 6,214,553; U.S. Patent No. 6,261,804; U.S. Patent No. 6,207,446; U.S. Patent No. 6,846,655; U.S. Patent No. 6,312,927; U.S. Patent No. 6,602,685; U.S. Patent No. 6,416,950; U.S. Patent No. 6,429,300; U.S. Patent No. 7,078,197; and U.S. Patent No. 6,436,665). Techniques to generate such biological peptide libraries are described in Dani, M., J. of Receptor & Signal Transduction Res., 21(4):447-468 (2001). One method to randomly generate peptides is by phage display. Since its introduction in 1985, phage display has been widely used to discover a variety of ligands including peptides, proteins and small molecules for drug targets (Dixit, J. ofSci. & Ind. Research, 57:173-183 (1998)). The applications have expanded to other areas such as studying protein folding, novel catalytic activities, DNA-binding proteins with novel specificities, and novel peptide-based biomaterial scaffolds for tissue engineering (Hoess, Chem. Rev. 101:3205-3218 (2001) and Holmes, Trends Biotechnol. 20:16-21 (2002)). Whaley et al. {Nature 405:665-668 (2000)) discloses the use of phage display screening to identify peptide sequences that can bind specifically to different crystallographic forms of inorganic semiconductor substrates. A modified screening method that comprises contacting a peptide library with an anti-target to remove peptides that bind to the anti-target, then contacting the non-binding peptides with the target has been described (Estell et al. WO 01/079479, Murray et al. U.S. Patent Application Publication No. 2002/0098524, and Janssen et al. U.S. Patent Application Publication No. 2003/0152976). Using the target/anti-target method, a peptide sequence that preferentially binds to hair and not to skin and a peptide sequence that preferentially binds to skin and not hair can be identified. Using the same method, Janssen et al. (WO 04/048399) identified other keratin-contain body surface-binding peptides (i.e., skin-binding and hair-binding peptides), as well as several other binding motifs. Phage display is a selection technique in which a peptide or protein is genetically fused to a coat protein of a bacteriophage, resulting in display of fused peptide on the exterior of the phage virion, while the DNA encoding the fusion resides within the virion. This physical linkage between the displayed peptide and the DNA encoding it allows screening of vast numbers of variants of peptides, each linked to a corresponding DNA sequence, by a simple in vitro selection procedure called "biopanning". As used herein, "biopanning" may be used to describe any selection procedure (phage display, ribosome display, mRNA-display, etc.) where a library of displayed peptides a library of displayed peptides is panned against a specified target material (e.g. hair). In its simplest form, phage display biopanning is carried out by incubating the pool of phage-displayed variants with a target of interest that has been immobilized on a plate or bead, washing away unbound phage, and eluting specifically bound phage by disrupting the binding interactions between the phage and the target. The eluted phage is then amplified in vivo and the process is repeated, resulting in a stepwise enrichment of the phage pool in favor of the tightest binding sequences. After 3 or more rounds of selection/amplification, individual clones are characterized by DNA sequencing. The peptidic binding domains can also be empirically generated from sequences reported to have affinity for at least one of human hair, skin, or nail. For example, peptides having an affinity for a human body surface have been described in U.S. Patents 7,220,405 and 7,285,264; In one embodiment, the peptidic binding domain comprises at least one peptide set forth in the group consisting of SEQ ID NOs: 1- 184,186-189,196-200,204-205, and 211-222. In another embodiment, the peptidic binding domain includes a hair-binding peptide selected from the group consisting of SEQ ID NOs: 1-134,184,186-189,196-200, and 211-222. In yet another embodiment, the peptidic binding domain is a skin-binding selected from the group consisting of SEQ ID NOs: 130-182. In other embodiments, the peptidic binding domain comprises at least one of SEQ ID NOs 196-200 or SEQ ID NOs. 210-222. In yet another embodiment, the peptidic binding domain comprises at least one skin-binding peptide selected from the group consisting of SEQ ID NOs: 130-182. In still another embodiment, the peptidic binding domain is nail-binding selected from the group consisting of SEQ ID NOs: 183-184. In addition to comprising at least one binding domain that binds to at least one of human hair, human skin, or human nail, the peptidic components of the invention further comprise the first part of an affinity pair. As used herein, "affinity pair" refers to a pair of agents having a known affinity for each other wherein the first part of the affinity pair was not derived from biopanning. Affinity pairs will be based on bonding associations that are not covalent bond- based, including, for example, ionic bond-based (electrostatic interaction), hydrogen bond-based, hydrophobic bond-based, chelation-based, biological affinity-based, or the affinity pair is based on a combination thereof. For example, affinity pairs of the invention may include ionic-bond pairs. "Ionic bond" pairs refers to an association complex of two moieties wherein one has a net positive charge and the other has a net negative charge. Ionic bonds, also referred to as electrostatic interactions, are among the strongest bonds, comparable in strength to covalent bonds, and are of long-range, on the order of 50 nm. (Isrealachvili, J.N., Intermolecular and Surface Forces, 2nd ed.; Academic Press: New York, NY (1992) pp. 32-34). Certain amino acids contain ionizable side groups, for example, the carboxyl groups in the side chains of aspartic and glutamic acids and the amino groups located at lysine, arginine and histidine residues. Some peptides often contain net charges (positive or negative) and certain charge distributions when any of the charged amino acids are in the peptide sequence. The net charges of the whole or portion of peptide molecule can induce electrostatic attraction with the oppositely charged second part of the affinity pair on the benefit agent, or induce electrostatic repulsion with the similarly charged second part of the affinity pair on the benefit agent. Examples of ionic (electrostatic) binding pairs include, but are not limited to, negative charged peptides coupled to positively charged particulate benefit agents, negative charged peptides coupled to particulate benefit agents comprised of or coated with a positively charged coating (e.g., anion exchange resins), positively charged peptides coupled to negatively charged particulate benefit agents (e.g., mica, silica), positively charged peptides couple to particulate benefit agents comprising a coating that provides a negative charge (e.g., cationic exchange resins having groups such as SO4"2). The charge and the charge density on the second part of the affinity pair on the particulate benefit agent can be obtained and regulated with proper surface treatments and pH conditions. Charges could originate from: 1) ionization of surface functional groups such as amino, carboxyl, sulfonic, and hydroxyl groups etc; 2) specific adsorption of ions from solutions. In this context, "specific adsorption" implies that the adsorption is partly of non-electric nature so that the adsorbed ions can create net surface charges. For inert benefit agents, multiple surface treatment approaches in the art could be used to create ionizable functional groups: 1) using oxygen plasma to oxidize the surface or plasma polymerization of specialty gas to create surface hydroxyl and other groups (C. L. Rinsch et al, Langmuir (1996), 12 (2995-3002); 2) forming self-assembled monolayers with terminal function groups, such as aminopropyl silane forming siloxane monolayers on metal oxide surface (Xia, Y.N., and Whitesides, G.M., Angew.Chem. Int. Ed. (1998), 37:551-575); 3) using layer-by-layer assembly process to adsorb polyelectrolyte multiplayer onto any surfaces to give charged surface with desired charge sign and charge density (Decher, G., Science (1997), 277:1232-1237); and 4) precipitation-coating of charged polymers or sol-gel. Surface charges of the benefit agents could be characterized by its surface isoelectric point (IEP), the pH value at which the net surface charges are zero. So at pH lower than its IEP, the benefit agent, in particular the second part of the affinity pair on the particulate benefit agent, bears positive charges; while at pH greater than its IEP, the benefit agent bears negative charges. Electrostatic interaction ranges can be further modulated with ionic strength: lower ionic strength provides longer interaction range, while higher ionic strength provides shorter interaction range. The modulation of the interaction range can be applied to obtaining stable peptide-benefit agent adduct at low ionic strength, but enhancing benefit agent deliver to body surfaces at higher ionic strength. The net charge of the first part of the affinity pair may be negative or positive depending upon the pH of the system. In one embodiment, the net charge of the first part of the affinity pah-is positive at a specified pH wherein the pH may range from 3.0 to about 10. In another embodiment, the net charge of the first part of the affinity pair is negative at a specified pH wherein the pH may range from 3.0 to about 10. Affinity pairs of the invention may also include hydrogen-bond-based pairs. "Hydrogen-bond" pairs refers to an association complex of the hydrogen atom of a relatively electronegative atom of one moiety with an electronegative atom of the other moiety. "Hydrophobic-bond" pairs refers to an association complex of two moieties in which both moieties have hydrophobic domains or characteristics that enable them to form an associative complex. The surface of particulate benefit agent may be hydrophobic. As such, one may incorporate into the peptide component a first part of the affinity pair that comprises an effective number of hydrophobic amino acid residues. The surface of the particulate benefit agent may inherently be hydrophobic or may be modified to have a hydrophobic surface capable of associating with another hydrophobic moiety. For example, the particulate benefit agent may be coated with a hydrophobic polymer using any number of well known coating techniques. A first part of the affinity pair that includes a hydrophobic peptide will typically be comprised of hydrophobic amino acids having a hydropathy index of at least 1.5 (Kyte and Doolittle, J. Mol. Biol. (1982) 157(157): 105-132). In one embodiment, the hydrophobic amino acids are selected from the group consisting of isoleucine, valine, leucine, phenylalanine, cysteine, methionine, and alanine. "Chelation-based" pairs refers to a coordinate covalent bonding complex of a Lewis acid and a Lewis base where the Lewis base donates two or more lone pairs of electrons to the Lewis acid. An example of chelation-based pairs is the interaction of various amino acid side chains and metal ions. Exemplary metals for use in chelation-based pairs include divalent metals, for example, nickel, copper, cobalt, and zinc. "Polyhistidine tags" are often used to bind to immobilized metal ions such as nickel, copper, cobalt, or zinc. The metal ion is typically incorporated into media such as nitriloacetic acid (NTA)-agarose, HisPur cobalt resin, iminodiacetic acid (IDA) resin, carboxylmethylaspartate (CMA) resin, TALON® (or any other immobilized metal affinity chromatography (IMAC) resin IMAQ. Metal affinity resins are commercially available from various vendors such as Thermo Fisher Scientific (Rockford, IL), EMD BioSciences (Madison, WI), and Clontech (Palo Alto, CA). The polyhistidine tag may be synthetic or a naturally-occurring histidine affinity tag such as "HAT" (KDHLIHNVHKEFHAHAHNK (SEQ ID NO: 185)). In one embodiment, the polyhistidine tag ranges from 6 to about 10, 6 about 8, or about 6 consecutive ("HHHHHH") histidine residues in length. In one embodiment, the peptidic component comprises at least one polyhistidine tag capable of binding to an immobilized metal ion on the surface of the particulate benefit agent. In another embodiment, the particulate benefit agent comprises an effective amount of an appropriate media on the surface of the particle. The metal chelate resin may be applied as a partial or complete coating on the surface of the particulate benefit agent. In another embodiment, the resin applied to the surface of the particulate benefit agent comprises a tetradentate metal chelator (U.S. Patent 5,962,641; herein incorporated by reference). In another embodiment, the affinity pair is a chelation pair that includes a polyhistidine-tag, i.e., an amino acid motif incorporated that consists of an effective number of histidine residues capable of binding to a resin immobilized metal ion with micromolar affinity, incorporated into the peptidic component and a metal ion incorporated into the particulate benefit agent, wherein the metal ion selected from the group consisting of nickel, copper, cobalt, zinc, and mixtures thereof. Other examples of affinity pairs of the invention include, but are not limited to biotin:avidin, biotinistreptavidin, streptavidin tags:streptavidin, maltose binding protein (MBP):maltose or amylase, glutathione S-trasferase (GST):glutathione. Affinity pairs can also be biological affinity-based. As used herein, biological affinity does not encompass antibody-antigen affinity. Antibody-antigen affinity is specifically excluded from the scope of the invention. In one embodiment, the affinity pair may include an epitope tag:antibody pair wherein the peptide-based reagent comprises the epitope sequence and the particulate benefit agent comprises the corresponding antibody. Examples of commercially epitope tags include, but are not limited to HA-tag, FLAG-tag, E-tag, S-tag, and myc-tag. In certain embodiments of the invention, the first part of the affinity pair is selected from the group consisting of a polyhistidine tag, biotin, a streptavidin tag, maltose binding protein, glutathione S-transferase, an epitope tag, HA-tag, FLAG-tag, E-tag, S-tag, myc-tag, and SEQ ID NOs: 185,206, and 223-234. In another embodiment, the first part of the affinity pair is selected from the group consisting of a polyhistidine tag, biotin, and SEQ ID NOs: 185,206, and 223-234. Optionally, the binding domains of the present invention can exhibit preferential binding for at least one of human hair, skin, or nail over other materials. For example, the binding domains of the invention may further preferentially bind to human hair, skin or nail over wool, cashmere, or yak hair. In another embodiment, the binding domains of the invention further preferentially bind to human hair, skin or nail over cotton or modified cellulosic fiber. In yet another embodiment, the binding domains of the invention further preferentially bind to human hair, skin or nail over metal, ceramic, porcelain, glass, silk, wood, polyester, or polyvinylchloride. The Benefit Agent "Benefit agent," as that term is used in the present invention, is directed to cosmetic compositions containing compositions or agents with properties that impart benefits to human hair, skin, and/or nail when deposited thereon. Benefit agents of the invention are in particulate form, i.e., the benefit agent is provided as small, discrete particles. The particulate benefit agents of the present invention have the second part of the affinity pair and are incorporated into a stable particulate dispersion having average particle size of between about 0.01 micron (10 nm) and about 75 microns (75,000 nm). In one embodiment, the average particle size is 0.01 micron to 75 microns, as measured by a light scattering method such as laser diffraction and/or dynamic light scattering. In some embodiments, the average particle size is less than about 60 microns, less than about 40 microns, or less than about 10 microns. In other embodiments, the average particle size is between about 0.2 microns (200 nm) and 0.4 microns (400 nm). In other embodiments, the particles of the dispersion will be nanoparticles, i.e., will have average particle size of between about 10 nm and about 100 nm. It will be understood by those skilled in the art that the "particle size" referenced herein will refer to the particle size measurements obtained using a light scattering methods such as laser diffraction (see ISO 13320-1:1996; International Organization for Standards, Geneva, Switzerland) and/or dynamic light scattering (see ISO 13321:1996) methodologies, both of which are known in the art. Exemplary systems are available from Malvern Instruments Ltd. Worcestershire, United Kingdom. It has been discovered that providing the particulate benefit agent in a stable particulate dispersion having average particle size of between about 0.01 micron and about 75 microns facilitates the coupling of the benefit agent to the peptidic component of the cosmetic systems of the invention. "Stable dispersions of particulate benefit agent" of the present invention, refers to particulate benefit agent particles dispersed within a sample matrix that is stable over time. As used herein, the term "stable" will refer to dispersions wherein particles dispersed within a sample matrix are stable over time. Particles will be considered stably dispersed when the average particle size of a sample remains fairly constant with time. In one embodiment, a sample is stably-dispersed if the average particle size of the sample does not increase by more than 100% over the initial particle size of the particulate benefit agent within 24 hours after dispersion formation. In another embodiment, the sample may be stably-dispersed if the average particle size of the sample does not increase by more than 50% over the initial particle size of the particulate benefit agent within 2 days after dispersion formation. In certain embodiments, there is no more than a 50% increase in average particle size within 3 days after dispersion formation. In other embodiment, there is no more than a 50% increase in average particle size within at least 5 days of dispersion formation. In still other embodiments, there is no more than a 50% increase in average particle size within 7 days of dispersion formation. In one embodiment, a particulate dispersion is stable when the average particle size does not increase more than 50% over at least 7 days, without the detection of any agglomerates larger than 50 primary particles. One of skill in the art will recognize that stable particle dispersions may have some settling over time, so long as the particles can be re-dispersed easily with a minimal amount of energy (e.g. gentle manual shaking/agitation that is typically associated with manual mixing/shaking to reform a uniform dispersion of particles within the cosmetic composition or cosmetic system). Means to form stable particle dispersions have been reported in the art including, but not limited to the use of sterically stabilized dispersions, dispersants, ionic dispersants, non-ionic dispersants, and polymeric dispersants, to name a few. Polymeric dispersants are widely used to stabilize pigments in coating systems such as paints and finishes, and in ink jet printing inks (Reuter et al., Progress in Organic Coatings 37:161 167 (1999), Schmitz et al, Progress in Organic Coatings 35:191 196 (1999), and Spinelli, Adv. Mater. 10:1215 1218 (1998)). The dispersant serves to form a shell around the pigment particle, i.e„ the particulate benefit agent, preventing flocculation and coagulation. In aqueous systems, the pigment dispersion is generally stabilized by either a nonionic or ionic technique. In the non-ionic technique, the pigment particles are stabilized by a polymer that has a water-soluble, hydrophilic section that extends into the water and provides entropic or steric stabilization. Representative polymers useful for this purpose include polyvinyl alcohol, cellulosics, and ethylene oxide modified phenols. While the non-ionic technique is not sensitive to pH changes or ionic contamination, it has a major disadvantage for many applications in that the final product is water sensitive. Thus, if used in ink applications or the like, the pigment will tend to smear upon exposure to moisture. In the ionic technique, the pigment particles are stabilized by a polymer of an ion containing monomer, such as neutralized acrylic, maleic, or vinyl sulfonic acid. The polymer provides stabilization through a charged double layer mechanism whereby ionic repulsion binders the particles from flocculation. Since the neutralizing component tends to evaporate after application, the polymer then has reduced water solubility and the final product is not water sensitive. Polymer dispersants, such as block and graft polymers, that provide both steric and ionic stabilization make the most robust pigment dispersions (Spinelli, supra). Polymer dispersants having both random and block structures have been disclosed. For example, Ohta et al. in U.S. Patent 4,597,794 disclose a random polymer dispersant having ionic hydrophilic segments and aromatic hydrophobic segments that adhere to the pigment surface. Ma et al. in U.S. Patent 5,085,698 disclose the use of AB or BAB block copolymers as dispersants for aqueous ink jet inks. The A segment is a hydrophobic homopolymer or copolymer that serves to bind to the pigment particle and the B segment is a hydrophilic polymer, or salt thereof, that serves to disperse the pigment in the aqueous medium. Ma et al. in U.S. Patent 5,519,085 disclose an ABC triblock polymer dispersant, wherein the A segment is a hydrophilic polymer that serves to facilitate dispersion of the pigment in water, the B segment is a polymer capable of binding to the pigment, and the C segment is a hydrophilic or hydrophobic polymer that serves to stabilize the dispersion. A combination of polymer dispersants may also be used, as described by Rose et al. in GB 2349153. While these random and block polymer dispersants offer good stability for the dispersed pigment, further improvements are desired for more high quality coating applications. For example, dispersants having a stronger interaction with the pigment would improve the stability of the dispersion. Moreover, a dispersant with a stronger interaction with the coating substrate would result in a more durable coating. This is particularly important for textile printing where enhanced durability is required. A self-dispersing pigment is a pigment that has been surface modified with chemically attached, dispersibility imparting groups to allow stable dispersion without a separate dispersant. For dispersion in an aqueous carrier medium, surface modification involves addition of hydrophilic groups and most typically ionizable hydrophilic groups. The self-dispersing pigment may be prepared by grafting a functional group or a molecule containing a functional group onto the surface of the pigment, by physical treatment (such as vacuum plasma), or by chemical treatment (for example, oxidation with ozone, hypochlorous acid or the like). A single type or a plurality of types of hydrophilic functional groups may be bonded to one pigment particle. Self-dispersing pigments are described, for example, in U.S. Patent No. 5,571,311, U.S. Patent No. 5,609,671, U.S. Patent No. 5,968,243, U.S. Patent No. 5,928,419, U.S. Patent No. 6,323,257, U.S. Patent No. 5,554,739, U.S. Patent No. 5,672,198, U.S. Patent No. 5,69,8016, U.S. Patent No. 5,718,746, U.S. Patent No. 5,749,950, U.S. Patent No. 5,803,959, U.S. Patent No. 5,837,045, U.S. Patent No. 5,846,307, U.S. Patent No. 5,895,522, U.S. Patent No. 5,922,118, U.S. Patent No. 6,123,759, U.S. Patent No. 6,221,142, U.S. Patent No. 6,221,143, U.S. Patent No. 6,281,267, U.S. Patent No. 6,329,446, U.S. Patent No. 6,332,919, U.S. Patent No. 6,375,317, U.S. Patent No. 6,287,374, U.S. Patent No. 6,398,858, U.S. 6,402,825, U.S. Patent No. 6,468,342, U.S. Patent No. 6,503,311, U.S. Patent No. 6,506,245, and U.S. Patent No.6,852,156. The disclosures of the preceding references are incorporated by herein by reference. The zeta potential indicates the degree of repulsion between adjacent, similarly charged particles in a dispersion. Colloids with high zeta potential (negative or positive) are electrically stabilized while colloids with low zeta potentials tend to coagulate or flocculate ("Zeta Potential of Colloids in Water and Waste Water", ASTM Standard D 4187-82, American Society for Testing and Materials, 1985). In one embodiment, the absolute value of the zeta potential of the particulate benefit agent is at least 25 mV. In another embodiment, the absolute value of the zeta potential of the peptide reagent-particulate benefit agent complex is at least 25 mV. The second part of the affinity part may be incorporated into the benefit agent in any number of ways. For example, the physical properties of the benefit agent may include the second part of the affinity pair. The second part of the affinity pair may be inherently present in the benefit agent or the benefit agent can be modified to include the second part of the affinity pair. For instance, in some embodiments, the benefit agent may be a charged colored pigment or dye, the charge forming the second part of an ionic affinity pair. The second part of the affinity pair may be an applied material or coating (e.g., a metal chelate resin) that has affinity for the first member of the affinity pair (e.g., a polyhistidine tag). In other embodiments, the second part of the affinity pair may be covalently attached to the benefit agent. Non-limiting examples of particulate benefit agents useful in the present invention include sunscreen agents, antimicrobial agents, sparkling particles, odor-control agents, conditioning agents, anti-fungal agents, fragrances, anti-lyses agents, aromatherapy agents, insect repellent agents, and the like. Non-limiting examples of sunscreen agents include inorganic particulates, such as zinc oxide and titanium dioxide; and organic particulates, such as methylene bis-benzotriazolyl tetramethylbutylphenol (available as Bisoctrizole from Ciba Specialty Chemicals of Basel, Switzerland). Non-limiting examples of particulate antimicrobial agents include silver-based particles and activated carbon-based particles. Examples of microspheres containing particulate benefit agents may include encapsulated or microencapsulated benefit agents, which retain the benefit agent within the encapsulation during application and allow the benefit agent to be released from the encapsulation at some desired time after deposition on the keratin-containing surface. Examples of odor-control agents include activated carbon particles and zeolites. The benefit agents of this invention may also be colored particulates, including colored pigments, colored particles, such as microparticles or nanoparticles, or combinations of these. Pigments, particularly metal compounds or semimetallic compounds, may be used in the compositions and methods of this invention in ionic, nonionic or oxidized form. The pigments may be in this form either individually or in admixture or as individual mixed oxides or mixtures thereof, including mixtures of mixed oxides and pure oxides. Examples are the titanium oxides (for example T1O2), zinc oxides (for example ZnO), aluminum oxides (for example AI2O3), iron oxides (for example Fe203), manganese oxides (for example MnO), silicon oxides (for example SiC>2), silicates, cerium oxide, zirconium oxides (for example Z1O2), barium sulfate (BaS04) or mixtures thereof and the like. Suitable pigments are commercially available. An example is Hombitec® L5 (INCI name: titanium dioxides) supplied by Merck. Other examples of pigments include the following: D&C Red No. 36, D&C Red No. 30, D&C Orange No. 17, Green 3 Lake, Ext. Yellow 7 Lake, Orange 4 Lake, Red 28 Lake, the calcium lakes ofD&C Red Nos. 7,11,31 and 34, the barium lake ofD&C Red No. 12, the strontium lake D&C Red No. 13, the aluminum lakes of FD&C Yellow No. 5 and No. 6, the aluminum lakes of FD&C No. 40, the aluminum lakes of D&C Red Nos. 21,22,27, and 28, the aluminum lakes of FD&C Blue No. 1, the aluminum lakes of D&C Orange No. 5, the aluminum lakes of D&C Yellow No. 10; the zirconium lake of D&C Red No. 33, CROMOPHTHAL® The Cosmetic System An exemplary method of using the cosmetic systems of the invention comprises the application of the peptidic component to at least one of human hair, skin, or nail. After a period of time sufficient for the peptidic component to bind to the hair, skin, or nail, the stable dispersion of particulate benefit agent is applied to peptidic component bound to hair, skin, or nail. The stable dispersion should be applied for a period of time sufficient for the first part of the affinity pair of the peptidic component to couple to the second part of the affinity pair of the benefit agent. Once the benefit agent and peptidic component are coupled, the affinity pair can be disrupted, resulting in the uncoupling of the peptidic component and the benefit agent. Reagents capable of disrupting the affinity pair will be based on the type of affinity pair used in the cosmetic system. Typical of such reagents are aqueous solutions including buffers having high or low pH or high or low ionic strength, as required. Certain methods of applying a benefit agent to at least one of human hair, human skin, or human nail comprise contacting the human hair, skin, or nail with a composition comprising a peptidic component having at least one binding domain which binds to at least one of the human hair, skin, or nail with a K