I enjoy public art. I'd love to hear more about public art, and public art like pranks (think the MIT Hack gallery). Another similar thing is: http://www.spril.com/StealthForceBeta/ from New Mexico Tech in the 1990s which I think I found on here.
I'm interested in both campus based pranks, and city-based public art both sanctioned and not. And anything else that involves leaving surprising things places. Fictional depictions, such as The Plain Janes by Cecil Castelucci, also welcome. Please send me more examples!