To read in the october issue of Scientific American, an article about Ballbot a robot using a new mode of locomotion. Introduced in October 2005 at the International Symposium for Robotics Research in San Francisco by the Carnegie Mellon University in Pittsburgh, Pennsylvania. As the name says, the robot is balancing on a ball or as the creators call it A Dynamically Stable Single-Wheeled Mobile Robot with Inverse Mouse-Ball Drive.

Videos of this robot are also available Video 1 Point-to-point motion and Video 2 Response to a disturbance

I apologize for any mistakes I could have made posting this topic.