At the SXSW Interactive official opening party (for which there was an actual evite) Microsoft and Frog Design set up an interesting Kinect hack. They had a small boxing ring, and inside the ring were two robot boxers, about the size of human boxers. On opposite ends of the ring, they had hacked Xbox Kinects set up (not the new Windows versions) with screens set up below them.
For each bout, a human volunteer from the crowd would step up to each Kinect, and Kinect would translate their movements into robot punches. The installation was a big hit with partygoers.