If you want to build a Linux application with motion controls, then you are in luck. Igalia has released an open source skeleton tracking library that works with Microsoft's Kinect input device. The Glib-based framework, which is called Skeltrack, supports tracking a single user and can monitor up to seven joints.
Igalia has previously released GFreenect, a GObject wrapper around the OpenKinect project's cross-platform libfreenect, which allows developers to obtain a video stream with depth data from a Kinect camera. GFreenect makes it easy to use this functionality in a Gtk+ application.
Skeltrack is designed to be used with GFreenect. As developer Joaquim Rocha explained in a blog post about the project, it uses algorithmic skeleton tracking exclusively and doesn't rely on a pose database. The implementation is partly based on a research paper(PDF) about real-time depth camera data processing. Rocha also published a video that shows how the library works in action. The result is quite impressive, as it picked up fairly nuanced changes in arm position.