Jedi Bot is a robot arm wielding a foam "lightsaber" that will try to attack or defend itself from human opponents. This system used the Kinect in order to track its opponent and was put together by students from Stanford. Of course, this is
not the first robot wielding a lightsaber, but it is certainly the first that can interactively fight a human. The video below shows the robot it action.
http://www.youtube.com/watch?v=VuSCErmoYpY
At the moment the robot is pretty slow, but nothing prevents the technology from improving with time and getting better speed, accuracy and strength... This might very well be the great-grandfather of General Grievous
General Grievous - Star Wars Episode 3
Via
IEEE Spectrum.