Sure, this ain't the first multitouch / rear-projection tv hack we've seen, but the thing is still rather novel. Using a 67-inch television, this guy put together a system that utilizes four IR laser line generators to produce a plane of infrared light across the entire surface of the screen. Two cameras mounted inside the TV look for the clusters of light generated when one touches the screen and tracks them using an app called tbeta for the Mac OS. If you'd like to build one yourself -- or if you're morbidly curious -- the kids at IDEO Labs have put the step-by-step out there in excruciating detail. Hit the read for some of that action or, if you really just like to watch, be sure to catch the videos after the break.

[Via Hack A Day]