Now that the iPad 2 has a front facing-camera and some decent horsepower under the hood, there's a lot of potential for really interesting camera-plus-screen co-ordination hacks. The clever folks over at the Engineering Human-Computer Interaction Research group have managed to combine a feed from the front-facing camera, with a bit of software wizardry, to track the position of a person's head in 3D in real-time.
They call it Head-Coupled Perspective and the result, as you can see above and past the break, is a 3D
