Impressive, but if I think back to some old examples of this kind of stuff, like Johnny Chan (also of CMU)'s headtracking/motion tracking with Wii-motes it had remarkably less data (IR Led points) but seemed to handle the type of usecases presented in the video just fine. Admittedly it uses camera technology rather than just photodiodes, so lumitrack seems to have an edge for things that need high speed/fidelity at very low cost, but I don't know what those applications are.