I would love to see some features added to Google Latitude and their mobile application. I think that with these minor additions, it could compete with services like Loopt.
- Add the ability to update "status" from the mobile application.
- Enable export into other social networks like FriendFeed and Facebook
Google's Latitude has one things that the other location based social networks don't have. With other social networks, the user has to maintain a completely separate friends list. Since Google Latitude uses your Google Contacts you don't have to do this separate maintenance.