There is some funny stuff on this web site I've linked below. I think I'd enjoy being part of one of the "Missions" they do.
Has anybody here been part of a Flash Mob or one of these improv Everywheres?
Improv Everywhere;
http://improveverywhere.com/2010/02/28/teds-birthday-2/
Sports Humor:
http://improveverywhere.com/2008/04/07/best-game-ever/