AT&T has just finished showing off what it's cooking up in its labs, and one highlight is a little project called ShadowPuppets that might make you reconsider the usefulness of a pico projector smartphone. The idea is delightfully simple: use the shadows created by your hand to control your phone when projecting an image. Pinch-to-zoom is supported, but you can also just move your hand towards or away from the projector to zoom in or out, respectively. You can also swipe your hand left to right or up and down to pan and scroll, and you just have to point to click. In practice it all worked quite well and fluidly, though the demo only showed us interactions with the browser version of Google Maps running on an Alienware laptop. The hardware itself is decidedly a proof-of-concept — it's just a 1.3-megapixel Logitech webcam paired with a MicroVision ShowWX laser pico projector.

What's the advantage of using shadows instead of the capacitive touchscreen? Well, the researchers say that they chose shadows because they look the same from every perspective, making it perfect for sharing and interacting with others. They also say that the tech could be used in group games, as well as in classrooms and board rooms for presentations, a place that many projectors call home. Unfortunately, the demo had to be run in a dark room — something that won't always be easy to find when you're out with your friends — but we were told that with brighter projectors such dim lighting conditions won't be necessary. It's important to note that while this demo was running on a laptop, we've been told that its demands are low enough that it could run on a smartphone without incident.