Bodybugg?

I once owned the actual Bodymedia model. It's the same thing as the bodybugg, but the original maker (or at least if I remember right it was). The bodybugg is what they market for the Biggest Loser.
I found it very helpful in tracking how many calories I burned throughout the day and that helped me gauge how much to eat throughout the day. It was really cool to see the different spikes in activity throughout the day to see when I was most active and the efficiency of my sleep to. I don't believe it is completely accurate, but fairly close and nothing will ever be 100%.
I actual bought mine on eBay. If I remember correctly I think I bought it for about $100 and ended up reselling it on eBay for about the same. Bodymedia just came out with a more compact version that I'm considering purchasing. Depending on what your goals are I think it is totally worth the money. Just keep in mind that if you get one of the older models you have to pay for the webservice to upload your information. I'm not sure how the bluetooth models work and how much it costs for the phone apps or what not.