Anyone check out the mocap stuff at GDC?

I didnt get to GDC this year, but I've been eyeing up that new cheapo mocap suite that NaturalPoint do (you know, the guys that do the head tracking thingy), its called optisomething.

Anyway, wondered if anyone had tried any of the low cost (i.e. around the 4k dollars mark) mocap solutions coming out. I heard there were a bunch at siggraph to (which I also missed).

Any review would be helpful.

Ta.