Teen Arrive Alive is a GPS-based service that works with Nextel cell service and can track where those Nextel phones are, as well as how fast they are moving and in what direction. Once you’ve signed up your child’s cell phone with the service, you can login to the Teen Arrive Alive site and see where they are. You can also have that information sent to your phone.
Along the same lines, you can get a Wherifone for your car and/or kids, which uses GPS as well and can monitor location, speed and direction. As if that wasn’t enough, Mealpay.com lets parents prepay for school lunches and then lets parents see what their kids order. MobileLime is another company that allows teens to use a mobile phone to buy items at fast-food restaurants, grocery stores and other participating retailers. The mobile phone is linked to a credit or prepaid card, so parents can check.