Someone else posted this guy's link in the crow feathers thread. I checked that one out because one of the birds I want for our raptor center is a crow....freaky smart birds. Anywho, this Ted guy built a coin operated peanut vending machine for crows.
Crows will teach each other what they learn, that's called "culture". His idea is to train some crows to pick up trash in a stadium after a game. When they drop a napkin or paper plate into a chute they are rewarded with a treat. Ok, so you got 5 crows trained to do this. They then show other crows in their murder how to get the treats. And so on until after games the crows just come flying in to clean up after the pigs that left the trash lying around. Ergo, crows are smarter than us. (That's my conclusion, not his.)