A research group at MIT has created a high-resolution, 3D motion tracking system that works through walls and other obstructions. From a static location connected to a computer, the system can track you as you walk around your house. Even when tracking you through walls or obstructions, it has enough resolution to detect gestures, such as lifting your arm. The system, called WiTrack, uses very simple hardware and software to perform the tracking -- as a result, it is much cheaper, economically and computationally, than existing systems such as Kinect that use computer vision to track you.