Jason Stevens from New York University's Interactive Technology Department developed the Kinect hack using a video projector, a Kinect, and the programming tools. The projector is used to relay the Kinect's output onto the client's body, and can be used as a colorful guide for the therapist. It works thanks to the Kinect camera's depth perception; it doesn't need the likes of green-screening to focus, and it can also judge the distance and movement of the body rather than relying on bright spots or colors.
While the therapist massages and moves parts of the body, the Kinect and computer translate the movements into a "flow field." In turn, the flow field is projected back onto the client's body, and therapist can then see the lines where he/she has already been -- these tracks are shown in red.
Jason's hack is still under development, as he is hoping to add further aids like live video (with goggles!) for clients to watch the therapist's flow fields. He believes that by being able to see the pretty lines on themselves, it creates an "".
to get a better feel for the hack: