The New York Times has the story, here:
In February, researchers unveiled a hummingbird drone, built by the firm AeroVironment for the secretive Defense Advanced Research Projects Agency, which can fly at 11 miles per hour and perch on a windowsill. But it is still a prototype. One of the smallest drones in use on the battlefield is the three-foot-long Raven, which troops in Afghanistan toss by hand like a model airplane to peer over the next hill.
