[bryanthompson]

My friend found the paper they published and I just read through it... Basically, they took a piece of plexiglass and polished the edges, then put high-power IR LEDs around the edges and put a video camera behind the glass. When you put your fingers on the glass, your fingers scatter the IR and the camera picks it up. Their own program uses the image to figure out where you're touching. My friend at UNO might try to build one.