AT&T on Wednesday announced the launch of a new service that lets subscribers on the same joint family plan track each other's locations thanks to their mobile devices. Called AT&T FamilyMap, the service lets parents or other account owners log into a website from a home or office computer or their own Internet-enabled smartphone and request the current location of other members on the group account.

A map view showing the location of a user can be toggled between a satellite image and interactive street maps. Users can also customize each handset they are tracking by assigning a name and photo to each phone number in the account, and often-visited places such as Home or School can be labeled as well. The service has other advanced options, such as the ability to receive regular updates on a specified phone's location at set times throughout the day, either by text or e-mail.

To ensure users' rights to privacy aren't abused, all users on the account receive a text message alerting them that they can be tracked, with regular updates to remind them of the fact. The account owner can also set the notifications to be sent out every time a user's location is requested. Owners also have the option of being notified of requests for a location, and can either allow or veto the request.

All of AT&T's postpaid (subscription) cellphones are compatible with the service, with location information being attained via assisted GPS. If the A-GPS system cannot be used to locate a phone, other methods will be used, likely involving cell tower triangulation.

The service for locating two phones is priced at nearly $10 per month, while up to five cellphones are covered by a $15-per-month subscription.