"Great product + review corrections"4.0 starson by cleanup
Pros: Seamless integration with iTunes & Nike.com; 3000 hour battery life; great Nike.com user interface
Cons: Only works with Nano (but your 5G iPod's hard drive would die if you ran with it); encourages purchase of new shoes
Summary: First of all, this is a great product. It's very inexpensive (much less than buying a GPS watch from Garmin or some other workout aid) and very convenient (sure beats using a treadmill and tracking your stats on a pen and paper). Unfortunately it encourages you to buy a new pair of Nike+ shoes, although you could attempt to mutilate your existing Asics or Sauconys to accommodate the sensor, as long as it's secure and doesn't fall out—the Nike+ shoes are still the best bet for securing the sensor, though.
Finally, the review is actually a little inaccurate. The sensor is not a pedometer, it's an accelerator. And you can calibrate it by running a specific distance before using it in your workout, and by entering your weight (to help calculate the amount of calories burned). It does not count how many steps you take, as some people take larger strides than others, but measures lateral movement (therefore it won't work if you use it on an elliptical trainer or a bike). Also, the battery won't die any time soon. The sensor has a rated operating time of 3000 hours. That's an hour per day for three years. By then you can spare another $30 for a new sensor.Updated
I mentioned the sensor was an accelerator. I meant to say accelerometer. Cheers!