Pong AR.
At the Sony booth at GDC 2012, I got my hands on a Playstation Vita running a demo of Magnet, clearly Sony's answer to the 3DS's AR cards and even has some very similarly themed features.
The first demo highlights the lack of a need for cards. The Vita sets out a series of green track markers that covers a surface. These work presumably the same way that those used by the filmmaking industry's compositing and color correction software, by finding a point of visual contrast in a moving digital image and sticking to it. This explains why, at the live demo, they used a black and red patterned rug to show the tech on; there'd be no chance of any of the points slipping (a problem that sometimes occurs in video work with the same tech) with very sharp, different-colored images to grab on to. That said, Magnet may not work as well on a clean white wall.
Rubber ducks can be placed anywhere the tracking points are placed, and the player can move over and around them to view them. The Vita also remembers where the tracking points were if you pointed it away and came back.
The second demo is a target shooter that can be placed on any surface and that maps a series of flipping targets that you can fire balls at. This demo is more like training for the next one, which features a dragon that flies in and out of the holes on a surface and shoots balls at the player, which they have to dodge physically, and fire back. This is surprisingly fun, and provides a challenge with having to duck and dodge, while also trying to target the dragon's head.
Lastly, I was shown a deformable terrain demo, that would let you push the terrain up by pressing on the Vita's back plate and push it down by pressing on the touchscreen. Later, after I'd played with this a while, the Playstation representative showed me how to drop a group of balls onto the terrain to see how they would interact or bounce around. Another mode in the same demo turns the terrain into liquid, rippling with each touch to the front or back.
At present, Magnet feels very much like a series of tech demos more than a set of games. A very cool set of tech demos, though. If they have more that continue to innovate simillarly, it might be well worth checking out.