Mark Hendrickson comes to that conclusion in The State of Location-Based Social Networking On The iPhone. Among the things that need to be enhanced:location updates in the background (Apple does not allow this yet),stability,ability to invite friends knowing they are supported handsets.
There’s a round up of the six most popular apps including Moximity which headed to private beta last week. One differentiator:it’s launching in one geography at a time. First up:hometown of Austin,TX. Also unique:the app pulls in your contacts from Facebook who are also on the service. There’s more coverage of the company in its local paper.