oh and just to make sure, Sony doesn't copy them, Microsoft also recently bought Canesta, the company behind Eyetoy.
Microsoft this week bought Canesta, the company which provided the gesture control technology behind the Sony Eyetoy – and immediately set the gaming community arguing over whether it was to stop Sony from having access to the technology or because its own Kinect “Project Natal” technology is still rough around the edges
Also a very innovative move by Microsoft.