Here's my proof-of-concept HD video of using a hacked Kinect camera for multitouch-like interaction. Written using libfreenect by marcan42 and libTISCH ( http://tisch.sf.net/ ) by myself.
I thought I'd get the mandatory picture-browsing stuff done so it's out of the way and everybody can focus on more interesting things :-)
Built on Ubuntu Linux using libfreenect and libTISCH.