(Yellow) Mivizu Nike+iPod Shoe Lace sensor Pouch for Nike + iPod Sport Kit
I have two foot pods that I use. I really like this one, because I never have any trouble with syncing or with the sensor being picked up. The downside is that it's not easy to take off if you use more than one pair of shoes. If this is the case for your, I highly suggest getting 2 or more. Then you can remove the foot pod using the velcro strap and without taking it completely off your shoe.