Meet the Shadow Bot: a cool humanoid robot that uses a Microsoft Kinect to mimic human actions. The developer uses a RoboBrothers RoboPhilo Humanoid Robot Kit, an Arduino Uno, a Breadboard, and a few other parts to complete the project. To play with it, simply stand in front of the Kinect device and move your arms. The robot will mimic your moves.
More information is available on Instructables.com.