For almost 30 years I have been picking up small, attractive pieces of plastic in the street. I chose these if they are either instantly appealing, or if it takes me more than a few seconds to decide. I did this unconsciously until Howard pointed out what I was doing. (Howard's web page is much more glamorous than this one). The collection lived for many years in a succession of plastic shpping bags, from the Exploatorium, American Express, and a European export cigarette company, Magic Seven. It would still fit into a 30 gallon plastic trash container, were I to decide to bag the whole thing.
Here are a few fairly flat, scannable pieces from the top of the heap:
Like this LP fragment, most modern recording media are made of plastic.
I once found a discarded underexposed photo of the Louvre, processed
in France, on the floor of an AC Transit bus in Oakland.
In France you get even the underexposed prints, and you don't get charged!
Based on a discarded catalog of Versailles, I now realize the picture is of the