Ben Wilson is a London street artist. In about as literal a sense as you can get: His art consists of miniature scenes and designs painted on used, discarded chewing gum—those petrified black spots littering city streets.
According to the BBC, Wilson's been doing this for six years, and made some 8,000 different paintings, which he photographs and catalogs. He's been arrested, though he seems to get along with the cops well enough, and he's even "a minor celebrity" in South Korea, which is... well, none of you can say that you're celebrities in South Korea, can you? Nor can you (or, maybe, would you want to) paint stuff like this:
You can see more of Wilson's stuff in this Flickr set, or if you find him in London and spit out your gum near him.