ave a look at this project I am working on. I'm using Kinect motion and 3D scanning sensors to track the position and orientation of peoples faces. Then I use that information to change the camera perspective in virtual pinball table simulators to make it seem as if the flat image has real depth.

This video will give you an idea of what's happening. The effect is quite dramatic and impressive in my opinion.

Video: Pinball Real Time 3D Head Tracking

Of course this project is still a work in progress. I am going to improve the cabinet with better aesthetics, but I hope the above video is effective in demonstrating the head tracking effect.