I came across this and found it amusing.
"At a Technology Entertainment Design conference in March 2008, Joshua Klein presented the potential use of a vending machine for crows. He suggested the crows could be trained to pick up trash and the vending machine would be designed to give a reward in exchange for the trash."
There is a link to the talk here:
How good would that be, eh? Crows picking up rubbish. You could give them little yellow jackets too.
Any one else got any suggestions of how urban animals could do jobs? I'm sure foxes might be useful, although I can't think of what for.