I like Star Wars like most geeks, but some of us take our love of Star Wars to extremes. One dude has taken a white plastic barrel and used it to construct his own R2D2 robot that he can ride inside. Details on the robot are scant.
What we know is that the dome moves, it has fans, and is self-propelled. There is no detail on how the person built the thing or what it is powered by. This would well be the most awesome Halloween costume ever.