I still can't work out what it actually does, and why I would want to join. Is there information anywhere about why I should be interested? Having visited htt

I still can't work out what it actually does, and why I would want to join. Is there information anywhere about why I should be interested? Having visited http://wheremyfriends.be/ http://wheremyfriends.be/ I gues it draws an animated map of where it thinks my Facebook friends are currently located. Is that it?