Gametrak Fusion -- Is this the Puppet Controller To Die For?

It appears there may be an inexpensive motion capture technology on the horizon (2007). From the specs, it is superior to the Nintendo Wii remote, as it uses ultrasound to detect exact 3-D positions at high speeds, and supposedly it gathers shape information about whatever you've attached the sensor to. They claim this could be used for collision detection and physics.

Also, it's platform-neutral, connects via USB, and will cost about $56.

One could build any number of puppetry controls with it! Virtual rod-puppets, marionette-controllers, shadow puppets. One could even attach it to actual puppets, driving virtual versions on screen.