Cars that drive themselves, planes that fly without a pilot — it sounds like something out of the film Transformers. But it's not science fiction anymore. Google has a self-driving car, and more companies than you might imagine are pumping out unmanned aerial vehicles, or UAVs, though you may be more familiar with the term "drone." Above is a slideshow showcasing a number of these robotic aircraft, most of which can be either piloted remotely (like playing a flight simulator) or can be pre-programmed to fly specific missions. They come in all shapes and sizes, and you may be surprised to find out what's already in our skies.