I just caught a demo of the Tactable multitouch surface, which grew out of an MIT Media Lab project. It's an impressive product, a mid-sized table with a sharp projector set underneath the glass. It uses an array of moderate-resolution optical sensors to tell where it's being touched, and the sensors have variable focus, so they can sense 3D gestures over the surface as well as contact with the surface itself. The projector's good and bright, and the picture looked good in a well-lit room (albeit a darker corner of same). And being optical, the sensors can also recognize objects laid on the surface, reading bar-codes, text, shapes, etc. It opens up a myriad of possibilities for game design, some kinds of creative workflow (sound and video editing) and other situations where novel UIs are apt to unveil new possibilities.
One thing I really liked about it all is that it's just a PC running a bunch of commodity hardware — a projector, some sensors — with cool software on the back-end. This is invention-by-recombination at its finest, and it means that the price and performance of the surfaces are tied to the broader markets for optical sensors, PCs and projectors, which points to a rosy future. The company's business model is building and selling the things, simple enough, so they don't make any pretense about top-s33kr1t stuff within.