The fitbit is a multi-axis accelerometer based pedometer, but it the main draw is that it wirelessly syncs data to the service when you are in range of the base station. Since it is a two way sync, data that you have entered on the website can affect the display on the fitbit itself. For example, your height or stride length entered on the website will affect the total distance value shown on the device.
In addition to helping you track your fitness, the fitbit claims to be able track how well your sleep is. Included in the fitbit package is an wristband. To track your sleep, you put the fitbit in "sleep" mode, and then place it in the wristband. I assume that the fitbit services calculates the quality of sleep from the percentage of time that the fitbit detects motion while in "sleep" mode.
There are one thing that I think that could be improved with yncing without a computer. The computers that we use most are laptops that are normally not connected to USB devices, so these will not be useful for syncing. And the desktop computers in our house are normally turned off. Using a cell phone would be a great solution. I see a few ways that this would work.
- Have the fitbit sync with a phone over bluetooth. Fitbit could write an iPhone or Android application that would send the data to the fitbit server
- Replace the fitbit device with an iPhone or Android application, assuming that the application doesn't decrease battery life of the phone.