Playback of 3D motion capture with a computer is nothing new, but how about with a solid levitating object? MIT's Media Lab has developed ZeroN, a large magnet and 3D actuator, which can fly an "interaction element" (aka ball bearing) and control its position in space. You can also bump it to and fro yourself, with everything scanned and recorded, and then have real-life, gravity-defying playback showing planetary motion or virtual cameras, for example. It might be impractical right now as a
