Pay it Forward.

Rosa's Fresh Pizza

I think this is pretty cool. This guy used to be on Wall Street, but left and moved back home to Philly to open a $1 pizza slice shop, after seeing how successful they were in Manhattan. At his shop, you can prepay $1 for the homeless to come eat a slice of pizza there. When you pay, you write a message on a sticky note and hang it on the wall, and that's your "ticket" for a prepaid slice. Pretty neat!