In recent years, ogliopeptides have enjoyed ever increasing interest in two areas: first, approaches to biomimetic enzyme-like activity; and second, as metal-free catalysts for enantioselective transformations of synthetic interest. The discovery and optimization of peptides for these purposes has often used the methodology of combinatorial chemistry. Examples include the screening of peptide libraries for ester and phosphate cleavage, aided by novel chromogenic and gel-based assays, and optimization of metal-free peptide catalysts for asymmetric epoxidation, enantioselective acylation/phosphorylation, conjugate addition to enimides, and hydrocyanation of imines (Strecker-reaction).