JP,
It's just that I haven't got TrackIR and I couldn't be arsed faffing around with that Free stuff, so I paid for this variant instead..
www.cachya.com
It cost me $15 USD and all I had to do was use my existing webcam and then print-out the Hat Sign Image and cut it out and glue to some card before I stuck it on a baseball cap. No LEDs involved and it works great.
GK