Hillcrest/Rift tracker : http://www.mtbs3d.com/phpBB/viewtopic.php?f=140&t=15282

libfreespace integration into source engine : http://www.mtbs3d.com/phpBB/viewtopic.php?f=138&t=15284

Hillcrest/Rift tracker support : http://www.mtbs3d.com/phpBB/viewtopic.php?f=139&t=15128

Head Tracker Roundup : http://www.mtbs3d.com/phpBB/viewtopic.php?f=120&t=14649&hilit=Headtracker+Roundup


Hillcrest FSRK-USB-2 :

6-axis
micro-B USB 125HZ / 250Hz
$ 99,00