Touchscreens can get kind of gross; after all, you are almost constantly rubbing them with your dirty fingers. It turns out the greasy filth that adorns your screen can actually be manipulated to look pretty neat. It's still gross though.
JK Keller has composed a nice series of GIFs that show off the way light can play across various designs drawn in human grease. They're nothing you'd want to hang up in the living room, but they're cool in their own way. Next time you're in a boring meeting (with sufficiently oily hands) give it a try. Maybe you'll create a true mastergrease. [JK Keller via Boing Boing]