Loopt, a Mobile presence application service, which uses emerging mobile and web technologies to develop a new way to connect to the friends, events and places around them has been launched.

Loopt turns your cell phone into a friend finder, it uses GPS to display the location of a user’s friends along with their presence status with detailed maps that show exactly who is where. You can put your friends on the map and see where they are & what they're doing. Also, you can put yourself on the map.  Show your friends where you are and what you're doing.

Loopt | Techcrunch

Loopt, Find your Friends Fast