Fitbit is an activity monitor which conveniently clips to pants, shirt or wristband and pays careful attention to what you are doing. It counts your steps, records distance traveled and tells you how many calories you've burned. When you're not being active it'll record data on how long it takes you to fall asleep, how many times during the night you awoke and how much sleep you actually managed to get. Go within a few feet of its base station and it will automatically upload the data to a website for subsequent detailed analysis and storage.
The device contains a three dimensional motion sensor not unlike the ones found in a certain popular motion-sensitive games console. The manufacturer describes it as a device that monitors the intensity and duration of your every move and converts it into useful information for later detailed study.
Cyclists and swimmers should note
It's been optimized to be sensitive to walking, running and general pottering around the house. If you're a cyclist you probably won't find it of much use, but the ability to manually enter activity information into the website might be of use in estimating calorie burn for pedal-powered workouts. Swimmers thinking it may be useful should note that although water-resistant, it's not waterproof.
After your daily activities are over, the personal activity monitor will record information about how well (or otherwise) you sleep and can even tell whether you're just lying there looking at the ceiling or actually asleep.
According to the company behind the product it has been designed for "people to get a general sense of their day and get motivation from improvements in their general day to day trends." The pedometer feature is claimed to be between 95-97% accurate, the calorie data is similar to that used in clinical research measurement devices and the sleep monitor gives similar results to polysomnograms found in sleep labs.
Bringing it all together
Once you've purchased your device (which comes with a base station, wristband and belt holster) you'll need to go to the website and download the Windows or Mac compatible synchronization software. After you've signed up for your account, access to all of the data analysis tools on the website is free. It should be noted that examining your activity information can only be done online - there's no stand-alone application to download.
The Fitbit will last about ten days before it needs recharging and it will store about seven days worth of data before needing to upload to the website. But uploading is fully automatic, all you need to do is walk within 15 feet of the included base station and your activity information is sent wirelessly to the website (provided the computer to which the base station is connected also has access to the internet of course).
As each device has its own unique ID, multiple users in the same household can upload individual information via a single base station. The Fitbit can be ordered now for US$99.95 (incl shipping) and, at this time, is only available in the US. At the time of writing, the company is currently filling back orders and will be unable to ship new orders until the end of October but customers won't be charged until their device has been sent.
Ed's note: this article was altered on 8/11/2011 to reflect current pricing.