Some guy bought the U-Command Wall-E RC toy and hacked it by adding servos and other components to make it a real robot. Looks like he added obstacle avoidance and some kind of 2D mapping although I don't know exactly how it works. Movement is very fast, maybe too fast. But very good job. The guy kind of shits on the toy in the video, but the version he made would be $150 retail or more. Mo' money, mo' motors.