Everyone complains about pigeons, that there's too many in our cities and they're a pest - thus could give them a use?
Mount small wireless camera's in a pigeon and thus the centrally located operations centre could view the pigeon's whereabouts and if they see anything suspicious take a snap shot from the pigeon closest!
Think about it, something dodgy going on and a plain clothed spy would only need drop some corn on the floor and the pigeons would descend!
Also by getting pooed on by a pigeon, may give a new meaning to 'just been caught'!-- Findus, Mar 22 2007 It's a fair coo, guv.
(sorry)-- theleopard, Mar 22 2007 random, halfbakery