The system is built on a small USB input device and a lot of sophisticated software, which the company plans to begin retailing next year for $70. For the price, users will be able to manipulate their machines with the kinds of gestures that are becoming more and more ubiquitous thanks to the explosion in touchscreen technologies--things like pinch to zoom, swiping between screens, or scrolling with the flick of a finger. The difference is that the user touches nothing; Leap 3D creates a four-cubic-foot interaction space in front of any computer that is more responsive than either a touchscreen or a mouse (and offers increased capacity for control by adding a Z axis to the touchscreen's X and Y axes).