four-channel GPS receiver using a repurposed FPGA board from a previous frequency synthesizer project. Connected to a PC running a console app, the receiver is capable of tracking four satellites simultaneously, which is good enough to capture lat, long, and altitude.
basically the Flash Nap project with a few extra features and some work. It's also a minimal version of "Light/Sound" hypnosis machines that cost hundreds of dollars, but if you have parts, this one will cost just a couple of bucks. NO PROGRAMMING REQUIRE
Nice little guide to building an IR transceiver - uses the USB port for stable 5V, but includes a link in the comments to a decent circuit diagram that uses a voltage regulator and therefore doesn't need the USB port for power.
a small device which plugs into a $20 prepaid mobile phone to make a GPS tracker. The Tracker responds to text message commands, detects motion, and sends you its exact position, ready for Google Maps or your mapping software