Anyone know of a place locally that buys old cell phones?

I'm building a sentient robot that will conquer the world out of all mine!

But seriously, there was a program a while back that accepted old cell phones for a charitable cause, I can't remember the who or the cause tho. Sorry.

(I've got a whole box of em myself)

Ebay 'em. There are always buyers for used phones in the range of $20-$30.