Silicone Skin Pouch For Nike+ iPod and Nike Plus Nike+ SportBand - Compatible with all Shoes- Magenta
I just started running a few months ago, which means I just bought new running shoes. So when I decided to try Nike+, I didn't want to shell out money for more new shoes. This is a great, versatile, much less pricey alternative.  I don't feel this at all while running (or cycling or doing the elliptical). The sensor fits pretty snugly, but that means it doesn't fall out! Once calibrated, the sensor matched the treadmill speed/distance almost exactly while it was in this pouch.