Neural Robotics Incorporated makes an unmanned helicopter called the AutoCopter that can fly in either remote control mode or GPS-guided fully autonomous mode. Pretty impressive, but it gets downright scary when you add a fully automatic 12 gauge shotgun to it. At less than $100,000 apiece, this is downright cheap from a military standpoint, and even within the reach of large corporations. Imagine a swarm of these smaller-than-man-size helicopters chasing you down the street.