In labs people have been experimenting with computer vision for a long time, like being able to track a body. We can go back almost 20 years and find examples of that at the MIT video lab, designing interfaces that track someone's arm or hand. It's really only with the release of the Sony iToy where that became something that was more public. And now with the Kinect, it's become massively public. So that's an example of the technology changing.