I've had quite a few pedometers in the past and used a lot of them for a while but I do almost everything online. I certainly track things with online tools. MyFitnessPal has been how I've kept track with my weight, food eaten, carbs, etc for months now. My Fitbit will sync up with my MyFitnessPal account and update the information there so I don't have to do it by hand like I do with Runtastic (The app I use on my phone to track my hiking & running.)
One of the surprising things I noticed as soon as I got the Fitbit was how small it was. On the webpage it shows it compared to a cell phone and it looks about half the size of the phone. I was prepared for a large pedometer. Then it arrived and it's TINY. It works in a pocket or clipped to a belt. I've lost them off belts before so I put it in my pocket and it's tiny and remains accurate even in my pocket. I counted today while I was walking and out of the 100 steps I counted it was within 4 steps every time while resting in my jeans' little coin/watch pocket.
The picture I've posted doesn't quite give away how small it is. It's just slightly larger than the quarter and very thin.