Popular Science describes a new camera that uses lasers to bounce waves off bodies and a camera to record the reflections. That allows it to track track body movements and even create an avatar in 3D. it can be used to drive the controls of video games and I'd guess mapping apps. I guess that means you could take that near holodeck-like walk in the Rockies or down the bike path here in Somerville. Tech Review offers more details of the technology.
via Tech Universe