Microsoft have made their Kinect software available via open source, which means there should be lots more cool stuff like this appearing.
It's early stages, but I'm just waiting for a giant projection on a building that's along the lines of 'Hand From Above' and 'Laser Tag'. Or, for someone to make a bit of ambient... I'm thinking Batman, against a night sky.
There's also a bucket load more here. Not bad for a being a week old!
All I'm saying is that programming geeks are cool.