(YouTube Link)
I'm not sure what this is, but it is awesome. Sticky Light is a student project at the Department of Information Physics and Computing at the Ishikawa Komuro Laboratory of the University of Tokyo. One source says this:
Sticky Light is a 3d tracking technology using a laser diode (low power), a pair of steering mirrors and a single non-imaging photodetector. The big difference to other tracking technologies is the fact that the Sticky Light doesn’t use a camera or projector. So what could you do with? It can track the contour of objects and even augment real-time drawings. Or you could build games like air hockey or a pinball game.
Official Website via Oh Gizmo!