I have a PS3 eye (came with the Sports Champions Pack).
Yes, the PS3 eye does allow you to use head tracking in GT5, but as others have pointed out, it only works in Arcade mode. According to PD this is due to the memory limitations of the PS3.
It does work. I've tried it. And it's kind of neat and a neat idea. But it's not without problems.
1. It only works in bright lighting conditions. Forget about using it in a dark or even dimly lit room.
2. It must be calibrated properly and correctly to achieve proper results. A process that may involve a constant back and forth until you get it right, unless you just hit the magic sweet spot on the first go. But if you move your seating position even a little or knock the camera you have to do it all over again.
3. If you use a large TV and sit in some sort of a rig, chances are you may be sitting too far away to use it effectively no matter how you calibrate it. If you sit 1.5m away or less you'll probably have better results.
4. The biggest issue (aside from not working in GT Life mode) is that there is an awful and annoying latency between moving your head and when the game reacts. And in this, I say it's a complete failure. It's natural that you'd have a small amount of latency but we're talking about .5 of a second or more. It may not seem like a lot but if you're in the 'heat of the moment' and need to quickly shift your head left or right, by the time you're looking straight, you're driving off the road because it's always a step behind you. And a side effect of this latency is that it gives you a feeling of motion sickness.
At least it does to me.
Perhaps it would work better if I glued a move controller to my forehead. Hmmm. Anyway, if you already have a PS3 eye, than you can always give is a shot to see how it works for you. But IMO, nobody should go out and buy one just to use with GT5. The eye itself, as a device is simply awful. My nearly 8 year old Apple iSight camera has nearly twice the fidelity when used for video conferencing.
