I just don't understand why people use the iPhone with Nike+. Have they not seen that big opening in the bottom of the phone with the metallic contacts? Last time I checked, you sweat alot when running. Sweat = liquid + salt. Liquid + salt + metal = bad. The iPhone is so expensive to replace when it's non-subsidized that I can't imagine taking that risk. I had an iPod nano that I used to run with and the contacts got corroded from my sweat. It got to the point where it would no longer sync with my computer. It wasn't a huge deal to replace, but the iPhone would be a much different story. For tracking purposes I use a Garmin 305.