I love this: Some smart alecs at UC-Santa Cruz recreated scenes from Donkey Kong in their building window using Post-It Notes.
I want to meet the genius who looked at those windows and said, "Hey, you know what we could do here?" And also the guy who wept when a bunch of the notes he was so carefully placing fell off. Because Post-It Notes stick pretty darn well, but you still know it must have happened.
(Thanks to Brad for the link!)