A few months ago, I signed up with Loopt. Loopt is a social network that allows you to share your location, and status, with your friends. I didn't do much with it, as I didn't want to spam my friends with invites for yet another social network. A few weeks ago, some of my friends got Loopt account, and I guess they saw that I had a Loopt account and they sent me an invite, so now I have people to broadcast my location to.
So far, I am not impressed. Maybe it is because I am updating status from my iPhone. Since Apple hasn't released support for applications running in the background, I need to constantly launch the Loopt application in order to update my status. What I really want in a location based updating service is something that I can set the frequency that my location is sent the service, and only if I want to change my status would I have to launch the application.
The other problem I have with Loopt, and other location base social networks, is that I have to maintain a seperate friends list. I have accounts on too many social networks, (Facebook, LinkedIn, FriendFeed, flickr, Google Friend Connect....) so I don't want to manage another list of contacts. Ideally, Loopt would use Google Friend Connect/Open Social or Facebook Connect, and then get the friends list that way.