Kinect Drawable Synthesizer and the Impromptu Sound Board
Cool take on the Kinect
You draw buttons, and they become key you can play. See the impromptu sound board video for a demonstration of drawing buttons.
Using the Kinect, I can create buttons by just drawing enclosed shapes on a piece of paper! The kinect identifies those regions as buttons that can be activated when I press them with my finger. This program uses ROS, the openni kinect drivers, and software I wrote here at MIT. You can find the code in the mit-ros-pkg repository.