Also http://www.thecrowbox.com/ were they apparently trained captive crows to pickup coins in return for food, there's also a TED talk the guy behind it gave. I've briefly looked at the 'Crowded Cities' page, I'm still not sure how the crows realise they get food though for cigarette butts? Does it rely on them randomly dropping something in the pot, and then getting food and continuing to do it?
I think this is where the part "tells other crows about it" line might come in. Perhaps they're hoping it works that way and they just train a few crows? This does seeem like a pretty important training point though.