From the folks at The Gearbox Project: magic courtesy of Google's mobile OS. Watch the video here to see a user control a robot ball's direction through an Android smartphone's accelerometer. Tilting the phone forward makes the ball move forward, and tilting to the side makes the wireless robotic sphere turn. You get the idea.
Gearbox plans to make its "smart toy" control scheme available via open-source APIs. The robotic ball runs on a 9-volt battery, receives control signals via Bluetooth, and relies on a bunch of servo motors to forge its own path.