Digital babysitting: tracking your child's every move with GPS

If you're searching for a way to keep tabs on your kid, look no further: GPS trackers can tell you where your child is at any given moment.

Child-tracking GPS products are gaining in popularity. Best Buy recently released the Little Buddy, under its in-house brand Insignia. The gadget costs $99 and it's designed to fit "easily into a backpack, lunchbox or other receptacle," according to BestBuy.com. More expensive models are also available, such as the highly customizable WorldTracker GPRS (*Est. $600) and the newfangled Amber Alert GPS 2G (*Est. $380).

So how do these devices work? Parents can set up what's called a geo-fence, which designates a child's safety zone. If the child leaves the safe zone, a text message notification is automatically sent to the parent. Using a cell phone or computer, parents can then monitor the child's location. Some models can also be programmed to alert the child that they have traveled too far.

GPS Magazine reviewed nine GPS child-tracking devices, awarding Amber Alert GPS and WorldTracker GPRS as its winners. The Amber Alert GPS is said to be "probably the most practical solution for parents." Positives cited by reviewers include its inexpensive price and ability to track indoors and out. They especially like the SOS button on the Amber Alert GPS, which allows a child to call for help, as well as the device's built-in speed alert feature, which notifies parents when a teen is driving faster than 80 MPH.

The WorldTracker GPRS is deemed "the most powerful tracking device" in GPS Magazine's roundup. It was found to work reliably both indoors and outdoors, and it provided the most advanced web-based tracking. WorldTracker GPRS can send location updates as often as every 15 seconds. Reviewers' only gripe is the WorldTracker's steep price: The device itself costs about $600, after which there's a $90 setup fee, followed by the recurring charge for the the tracking service, which runs about $69/month.

Understandably, GPS trackers may spark controversy among families. While they certainly appeal to parents concerned about their children's safety, some tracking subjects, especially teens, see these devices as an infringement of privacy rather than a security measure.

Another factor to consider is cost. The units start at $150, but, as demonstrated in the WorldTracker's price breakdown above, many GPS trackers also have monthly or annual fees attached to them. Some devices even charge per tracking session, so be sure to do your research and fully weigh the costs and benefits before purchasing a GPS tracker.