Apple and Nike recently released a product just for runners that integrates running shoes and an iPod. There is a little device you stick in your shoe that keeps track of distance, time, calories burned, etc. and wireless sends that data to your iPod nano. You plug your iPod into your computer after each run and it downloads your running data into some running workout training app. Nike wants you to buy special shoes, but I've read different and creative ways people have been using this gadget with their existing shoes.