Wiimotes on your feet...
I can already see motion capturing with Wiimotes.
But then I also see a small problem because the Wiimote has a forward-looking camera which has to be pointed at the sensor bar if I'm not mistaken, that would mean if you turn it too far into one direction, it will lose track of the sensor bar and thus you'd lose control. This problem would increase the closer the Wiimote is to the sensor bar and if I'm not mistaken, that's why the Track IR has such a sensor "bow" or array so it can cover a wider angle and thus find the infrared lights in a wider angle which should be useful if you're sitting close to it at a desk. Don't they recommend using the Wiimote 2m away from the screen anyway?

Also next up, infrared-guided missiles using a Wiimote.