The latest Micro Air Vehicle from MIT does an incredible job of balancing itself in-air. Not to mention that the helicopter models its surroundings so well it could probably fly over to the fridge and make you a sandwich.
By using lasers and 3D cameras, the team built a vision engine that can very accurately define the helicopter's surrounding environment. That's only part of the trick to getting it to fly so well, the other half is some pretty sweet flight path correction. Think of it like a flying Big Dog. Check out what happens when the guy pokes it with a stick.