Sprint seems to be a huge fan of rolling out handset-based tracking and location services. It's latest, dubbed "Friend Finder," uses Loopt's technology to allow Sprint subscribers to get that social networking on while wireless. Like other LBS applications, the GPS chip inside that handset is used to update a customer's location every 15 minutes. Of course, all your friends must have Sprint phones as well as being Loopt customers, and friends have to grant access for you to track them. This is similar to Helio's Buddy Beacon service which launched in 2006. Cost? Sprint will make ya pony up $2.99 a month, and the service will initially work on 25 handset models from the carrier.