Only law enforcement can legally track an individual via cell phone without their knowledge. It can, however, be a helpful way to keep track of loved ones, especially children. GPS tracking has the potential to provide a good service to those who will use it properly.
Cell Phone Carriers
To do this legally, you will need a cell phone that is GPS-enabled.Many cell phone carriers offer GPS tracking services. Some track anonymously and others send text messages to the handsets of the phones being tracked. If available, scheduled checks can be performed. For example, parents can schedule checks at bus pickup or drop-off times. Check with your carrier for specifics on available features.
There also are online services such as Helio, Boost, and Loopt that offer buddy-to-buddy tracking. Only those who sign up for the service can be tracked. It's a voluntary service and carries the ability to block, delete and add members.
Beware. Many sites claim the ability track any GPS-enabled cell phone. At best, most of these services can only pinpoint a location to the nearest city. Any service that can provide a more accurate location may be violating the law.
Tracking someone via GPS-enabled phone without their permission or knowledge raises invasion-of-privacy issues. Used ethically, however, the technology can provide great benefits -- tracking and locating lost children and family members. The technology also is being used in automobiles and laptop computers to help locate them when they are stolen or lost.