When it comes to flying around indoors, helicopters and their ilk get all the attention. That's generally because your typical plane is best suited for flying forward fast, not "painstakingly avoiding obstacles." This drone from MIT is an exception to that rule.
Using a pretty standard Intel Atom processor, some on-board sensors, and some sophisticated calculations, this plane designed by MIT's Robust Robotics Group is able to dodge obstacles with ease, even at high speeds. It'd be impressive enough to watch this sucker cruise through a closed course, but to really prove its mettle, they brought it to a parking garage, where it completed a seven minute flight at 35km/h, covering roughly three miles in distance, and coming within inches of collision. Take that, rotors! [MIT]