SPASM for Live integrates spatial audio into a popular audio software.
In the latest version, which used Kinect tracking, the program can distinguish user movement and sound placement by color. In the first case, the listener's position and orientation can be controlled (user tracking); in the second case, three sounds can be manipulated according to its position (audio effects).
The listener uses (ideally) headphones, to be always in the sweet spot. These headphones have an iPhone integrated which allows to track the user's orientation, while Kinect detects his position in space.
SPASM which stands for Spatial Audio Sound Mixer was started by V2_Lab in 2008. Now, in SPASM for Live computing and audio were separated. The first is done in MaxForLive, and controls the audio part in Ableton Live. The whole software package will be downloadable in the near future.