I just got the Nike Runners Sportband which I'm finding quite useful. It tracks:
1. Distance
2. Pace
3. Miles
4. Calories burned
5. Time
There's a small chip that goes inside your shoe (don't worry, you cant feel it) and a wristband that looks like a small watch. The two pieces communicate to eachother. All the info goes straight to the wristband. At the end of your run, it gives you all the info to review and upload on your computer if you so desire. Sounds high techy, but super easy to use.
Oh and, no, it will not interfere with the nano or any other iPod or electronic device you may wear.
Note- if you're going to get the Sportsband, be sure you have Nike + shoes. You can get the sportsband on amazon for about $60.
