what a name for a tunneling mechanism. jefferson y. han shows how visual work based on frustrated total internal reflection looks like. or better, his cheap 'crazy multi input touch screen' does the job. (another url for the video)

...ftir is a phenomenon familiar to both the biometric and robot sensing communities. It acquires true touch image information at high spatial and temporal resolutions, is scalable to large installations, and is well suited for use with rear-projection. (acm paper, via robert)

in the paper han gives credits to some older work on ftir, por ejemplo: Mueller, R. 1974. Direct Television Drawing and Image Manipulating System. U.S. Patent 3,846,826. Nov. 1974.

after the i/o brush from mit another nice work. some similar stuff has been around ars electronica, and i remember, that i have seen another installation in barna as well. but i don't remember its name. it was a nice one, though as they captured the movement of the people and displayed it on screen in a similar way as in the han piece. included was a kind of fade out effect, but there was nothing you needed to touch. just moving was required.