Last December, I wrote about Microvision’s laser-based micoprojector that could potentially put a video projector into portable devices like cell phones and PDAs. Now 3M has announced a technology demonstration of an LED-based microprojector that’s about the same size as the Microvision design and can project a 50-inch-diagonal image on a wall in a reasonably dark room. It’s also targeted at the same end applications. Not much technical data yet, but an industrial-cool video: