The 'locator' is the cel phone. It's generally gps on a chip (installed on the motherboard) or an extra antenna to the main cpu which does the gps calculations. The location is simply a function and cannot be removed from the phone and used otherwise. gps-based locators can be built/bought (usually bought for cheaper than built) -- and can have whatever features you want -- needed parts: gps receiver (spits out location data) cpu (to log or translate the location) transceiver (can be cel phone or other radio) to get location to somewhere else. Google Lattitude does...just this -- on a smart phone enable the program and it will broadcast your location to people you want. DIY versions can be found, search "gps tracker" or 'diy gps tracker'