Track your rides and runs via your iPhone, Android or GPS device, analyze your performance, and compare with friends.
Lucky you missed it. We saw one on HER yesterday and they looked nastt
(correction) and they look nasty.
Nasty and I'm just going to say it...stupid!
I just don't get the point of them.
The people I know that have them love them. One of them is a 45 year old 2:40 marathoner who recently started using them for non-impact training (that can still be done outside in the fresh air).