Hi Andrew, you might try Adaptive Optics Associates. They sell a Multi-Trax
both 2d and 3d trackers. Their phone is 617-864-0201 fax 617-864-5855
(Massachusetts) They also sell other systems and analyzers for both animation
and modeling. If you are into character animation take a look at SimGraphics's
VActors, they support various input devices all wireless for tracking both
facial and body movements.
This systems by the way are pricey but they do what they are supposed to do!.
Say hello to Tim.
Arturo (From the Tyrian team)