This is a really interesting proof-of-concept. People don't seem to be grooving on the idea of leaving a GPS signal running on their phones all the time, but they do seem to be willing to say "hey I'm going to such-and-such bar right now" and have it automagically SMS'd to all their friends.
However, I'm told that after Google acquired the company, they started to just strip it for parts, and the whole staff of Dodgeball quit on a Friday the 13th in disgust.
I wonder what it's gonna take to get location based phone stuff to be accepted by people. There's gotta be some killer app that'd get folks to feel safe using it.