Modern Moist Towelette Collecting.

Yeah, those things you get when you order wings, fried chicken or some other messy food. There is actually a whole website dedicated to collecting them and it's called
Modern Moist Towelette Collecting. They even have a theme song. More proof that some people have wa-a-a-a-y too much time on their hands.

Thanks to Jeff Houck of The Stew