see http://forums.bistudio.com/showthread.php?t=72510
@ IceBreakr:
The most expensive thing you need for Free Track is a webcam (30 fps) or better a original Wii Remote Controller (100 fps). --> 35 $.
I have chosen the Wii Remote Controller for which you also need a Bluetooth Dongle. --> 10 $
Then you need a cap and three IR diodes and resistors. --> 4 $.
After some (very easy) handicraft work (), you have your own FreeTrack: