Love it. Maybe people can even put a status that shows up for their friends. "On Trail" or some such.
Hmmm, that status could even be used as a where you are/when to be back/when to worry/when to call rescue format. My wife travels a lot for work and I either go places alone or stay home. Having someone, or a group of someones, know where we are might be a real boon.
Imagine if we had an "On trail" status list with the duration of the ride in hours. Then we can know who is overdue.
I know more than a friends list. But those friends can help keep you safe.