If you like to classify things, or see classifications of things that other people took the time to do, you might like the work done by the Holotypic Occlupanid Research Group (HOLG). Their focus is perhaps fascinating, and certainly fastener-centric. The HOLG web site explains:
This site contains several years of research in the classification of occlupanids. These small objects are everywhere, dotting supermarket aisles and sidewalks with an impressive array of form and color. The Holotypic Occlupanid Research Group has taken on the mantle of classifying this most common, yet most puzzling, member of phylum Plasticae.
Here, a photo from HORG’s variegated collection:
(Thanks to investigator Fluffy for bringing this to our attention.)