It's great being at the top of the food chain. That means we can use animals for our own devices. Sorry, PETA, but that's the law the jungle. And here's a great example of our cooperation with (or if you prefer, enslavement of) animals, this time with our friends the pigeons. A flock of 20 of the birds will be enlisted to fly over San Jose, California this summer, checking for pollutants such as carbon monoxide and nitrogen dioxide. Researchers will equip each pigeon with a GPS receiver and air pollution sensors. Just to be sure all this is properly documented, each member of the flock will be decked out like a tourist, with a miniature camera hanging around its neck for aerial picture taking. All the resulting data will be sent back to home base using a miniature self-contained backpack that contains all the necessary gadgetry in addition to the guts of a cellphone. Watch for the results of this unique reconnaissance mission in August, where its data will be displayed on the Web in the form of an interactive map.