This deal has ended.
Update: the kit is currently out-of-stock. Sports Authority has the best deal yet on the Nike+ iPod Sport Kit (as well as the Nike+ Sport Armband). This is the super-cool sensor and transmitter that allows an iPod Nano to keep track of your runs. It is $29 but if you spend $1 more (buy something cheap like these socks for $4.99) you can get $10 off by using Google Checkout, cutting the price of the kit to $19, effectively. Also, shipping is currently free (it is usually not) and there is no sales tax (except KY, PA). Nike products are usually excluded from coupons but do work with the Google Checkout promo.