I've been avoiding the glorified Wii Fit
bathroom scale for a couple years now--I'd rather just run around outside to get my exercise, mostly because it doesn't cost $100 to do it. However, researchers at the University of Maryland and my alma mater, The Ohio State University, have found
the Wii balance board to be a cost effective alternative to devices used to determine if athletes have concussions. According to the Engadget story, doctors can measure an athlete's balance and coordination with a few of the minigames that come standard with Wii fit.
The professional force plate sensors will always be more accurate, but those cost tens of thousands of dollars. For a solution that works "pretty decent" according to the doctors, the Wii balance board is a real bargain. I've never found Wii Fit to be very effective at weight loss, but it's cool that it's helping people who stay fit for a living.