Getting Fitbit

Some people thrive on data, and like to measure, quantify, classify and graph. For obvious reasons, these people tend to gravitate toward fields like programming and engineering--fields that require a lot of sitting in front of a computer and not getting much exercise.

In other words, there's a lot of fat nerds out there. Fortunately, there's also the Fitbit.

Last fall, San Francisco-based startup Fitbit launched its namesake product, the Fitbit Tracker. It's a small plastic gizmo containing a 3-D motion sensor, something like what's inside a Nintendo ( NTDOY.PK - news - people ) Wii controller. Clip it onto your clothing, and it logs your movements throughout the day.

It may sound like just a fancy (and at $99, expensive) pedometer. But the high-tech Fitbit is much more. Because it follows your movements in three dimensions, it doesn't just count steps--it knows how much you've been exerting yourself, if you've been sitting, walking or running. It also knows when you did what, so it can tell the difference between someone who is constantly on his feet, vs. an otherwise sedentary person who takes one long walk at the end of the day.

Fitbit even wants to track you when you're not moving at all. Strap the gadget into the included wrist band and wear it while you sleep; the tracker can tell when you wake up, or toss and turn, providing insight into the quality of your rest.

Better yet, the Fitbit comes with a base station that plugs into your computer, and communicates wirelessly with the tracker. So all the information about your day's activities is automatically and seamlessly uploaded to Fitbit's secure servers, allowing you to log on to their Web site and view all kinds of graphs, data and details about your active habits. Fitbit also allows users to log their meals into the Fitbit Dashboard Web portal, so the result is a robust, one-stop control center to keep track of your diet, fitness and health.