I'm in love with my fitbit. I received an ultra for Christmas and it is AWESOME. Basically it's a little step counter that I wear at my waist. And actually I'm a first adopter because they just announced a wrist band instead of a little clippy guy. I hear the wrist band doesn't show a step count actively and I need that step count on the click of a button to spur me to take more steps. But listen - it might be the gamer in me - I have started walking at lunch because my step count is below what I feel it should be. Fitbit automatically sets a goal of 10,000 steps a day...and my first day back in the real world I only hit 6,000 (holiday/vacation days don't count as I am a motionless lump). After walking a bit every day at lunch I'm getting closer to 10, though to be fair, even with a 20 minute walk I'm currently at 8512 steps.
It also tracks my sleep - I can wear it on my wrist and it tells me how often I'm highly active every night (the answer is about 5 times on a good night...more on a really tossing/turning night). The night before I got sick (we had a touch of the flu in the house) it cataloged my really poor sleep for me. At this point I'm not wearing it to bed every night - it was interesting for a few nights and then it was basically the same. I will admit that it was a fun measure of what time loml gets in bed every night.
So yes, tracking my steps has been awesome. And maybe even neater for me is my fitbit scale. That's right, my scale - my weight and fat percentage is beamed via my fancy wifi scale to my fitbit account and I can track my progress online. See how active I am, what my weight is, how many steps I climbed. All with little to no effort on my part (I clip my fitbit on every day. That is the extent of my effort).
I have a streak of statistical mathy nerd in me - charts and percentages really make me happy (you should see my RSVP document for our wedding, it calculates all kinds of things, for fun). So the fitbit is right up my alley. Do recommend.