I've got a FitBit HR - it was a bargain at something like £60 last year, so I bought one to see the effects of doing a lot more exercise. It's pretty neat, although you'll need to keep it paired to a smartphone via Bluetooth to get the most out of it.
I like it, but it's only really useful if you're monitoring exercise I'd say - unless you want a gadget for all the data! I'm on the fence about how useful it is, but I do quite like gadgets .
Both of my daughters have them. They find them useful for monitoring what they've done each day, particularly the number of steps they've taken. They use the figure as an incentive to try and do more the following day. They have both lost weight since getting them but, of course, watching what they eat is equally important.
I don't have one as I don't need to lose weight and I get quite a lot of exercise.
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