Gamereactor interviewed Virtual Air Guitar's Teemu Mäki-Patola about the upcoming PSN title Kung-Fu Live:
"Q. So, Kung-Fu Live is squeezing a lot of power out of the PS Eye - how does it compare to what we're seeing from Kinect? What are the technical limitations, and how do you overcome them?
Our Freemotion technology is doing similar stuff. For instance, in addition to removing the player's background we also track the player's skeleton, which is used for various things such as collision detection, pose recognition, movement exaggeration and detecting special moves. The difference is that we are doing this with a normal 2D web camera. Detecting depth of the player's moves is harder."