A few weeks ago I showed a video of me appearing to control Jmol simply by waving my arms around. Now you too can appear to control Jmol in this way.
My instructions are going to be minimal, so your mileage may vary, but here goes...
1. Get a Kinect. You don't need to buy an Xbox. The Kinect costs about 150 euros.
2. Install all of the Kinect drivers and so forth. I'm on Windows and I followed the instructions by Vangos Pterneas (note that I needed to follow the "Troubleshooting" section to get things to work). Ben O'Steen was using Ubuntu at the hackfest and followed the instructions at keyboardmods.
If you did it all correctly, when you plug in your Kinect the driver should be found by Windows. If it isn't, just go through the instructions again.
Once the Kinect is installed, in your Windows menu try OpenNi/Samples/NIViewer - this should give the view from the camera and depth sensor. Also try PrimeSense/Samples/PointViewer to play with hand tracking.
Image: Creative Tools