Well, from the super-smart to the super-small: In the way of science applied in cool ways, apparently the pentagon has developed a new "nano-UAV" built to look like, and fly like, a regular hummingbird. Check out the video.
The robotic hummingbird was built (somewhat obviously) for spy purposes. It's still in testing phases (it's maximum flight time right now is about 8 minutes). However, flight time will not be the only thing the designers have to fix. As one author put it, the robot only really works as a spy if "that area has a population of hummingbirds -- the usual reaction to seeing a hummingbird here in midtown Manhattan is something like 'OMG you guys look at the hummingbird!!!!!!,' which is not necessarily an ideal situation for a spy-drone."
Whatever its future in espionage might be, it's really cool.