celtic_hackr writes "Well, I never thought I'd be an advocate for placing GPS devices on people. However, since it took less than three days for my local school district to misplace my daughter, I have decided that something needs to be done. By the school district's own admission it has a recurring problem of placing children on the wrong buses. Fortunately, my daughter was located, with no thanks to the local school district. Therefore, I would like input on a way to be able to keep track of my child. I know there are personal tracking devices out there. I have nothing against these systems. But I want more than this. My specification are: 1) a small unobtrusive device I can place on my daughter, 2) an application to pull up on any computer, a map with a dot indicating the real-time position of my child, 3) a handheld device with the equivalent information, 4) [optional] a secure web application/plug-in I can install on my own domain allowing me to track her from anyplace in the world, 5) a means of turning it all off, 6) a Linux based solution of the above. I believe all the pieces for making such a system are out there. Has anyone built anything like this? Is there an open source solution? How would I go about building my own? Has anyone hacked any of these personal trackers before, to serve their own purposes? How does a tinfoil hat wearer engineer such a device to make sure Big-Brother isn't watching too? Can these devices be locked down so only certain devices can pick up the GPS location of an individual locator? What other recommendations do you have?"