I use Tasker on my Android phone and set up a profile that will activate when it recieves a text with the phrase "locateme". It will turn on the GPS, grab the location, plug that into google maps and get the URL and then email me that URL so I can see exactly where in the world it is. I also have another option for if it's lost in my apartment (such as under the pillow) that response to "findme" and crank the volume and starts alternating between an alarm sound and vibrating until I find it.
