Does anyone else use their nano as well as the nike + tracking system for running? I just got new Shox and I picked up the nano shoe insert too. I ran with it for the first time yesterday and found it encouraging and motivating once I logged on to nikeplus.com and realized how detailed the tracking system is. The part where you can initiate challenges with other users seems awesome. I'd love to set something up with other people who might be using it the same way I am. We could track each other's progress on a daily basis. Challenges can be based on total miles, total calories burned, etc... You can set up challenges for any length of time. Anyone interested?