To me there’s three main location based apps for the iPhone: Brightkite, Loopt and Whrrl. The others are playing catch up and have a long way to go. I’m still waiting for google to update their google app with latitude feature to see how that affects my use of the other location based apps, but until then my favorite is Brightkite.
What is your favorite location based app? Do you use location based apps at all or you don’t like anyone (big brother) checking in on you.
Did you enable the gmail location signature feature?