I take a look at the Nike+ Fuelband, similar product to jawbone, fitbit and other sensor fitness devices.
These have the same motion sensors as in your smartphone and do a pretty good job figuring out when you are running or walking. Nike+ has figured out a way to give you fuelpoint based on your details, so that your daily goal is to reach a certain amount of point.
Out of the box, your goal is 2000 fuelpoints. You can change that to either 3000 or 5000. A USB cable is also provided out of the box. You can charge the device wither with the cable or without. Note that you should load up the Nike+ software onto your computer before you plug it in. The software will transfer any activities to the nike+ running website and update the device with any firmware (which is fairly often).
The device gives you an approximate idea of your activity. If you are a runner, this won’t give you the level of detail you need in terms of distance, speed, etc… You are far better getting a Garmin Forerunner 10 for the same price. However, if you want an idea how active you are during the day and need a little motivation to get up and go for walk to get to your daily goal, then this might be something to look for. The device will display fuel, time, steps & calories and you can set it to only display fuel & time. As a watch, it is actually pretty stylish with the old school LED display. Once you hit your goal, you will see an animation. If you are a iPhone user, you can also transfer activities via bluetooth with help of the nike+ running app.
How much activity do you need to reach 2000 or 3000 points? Well for my details, I work in a cube all day and I need to walk the dog for an hour and run for 20 minutes to reach 3000 points. Basically 90 min of activity. You can’t combine fuelpoints from the fuelband and other nike+ products like running and footpod.