To FitBit or Not to FitBit

In my neverending quest to find techno items and tools that will encourage and aid me in weight loss, I have stumbled upon the Fitbit family of products that looks like something I could use, but to be honest, I don’t know which would be best for me, is it worth it, would I use it?? I DO use MyFitnessPal on my smart phone (OK, well, I HAVE used it, but maybe I’ve slacked off now and need some encouragement to get back on that wagon) and I think I read that the Fitbit interfaces somehow with that.

FitBit Fun

Does anyone around here use a Fitbit? If so, which one do you like best, and why?