I just started a new project called "FindMyPhone". It's supposed to be a robust and 100% free app to let Android users find their lost or stolen phone.
Currently I'm letting the user sending an SMS with a secret text to the phone and then get an automated response back with the location in an Gmaps-URL.
It uses the GPS and currently it's not at all as robust as I wish.
Future additions should be:
* Continious GPS updates via some kind of central server. Maybe via blogging API?
* Using alternative communications channels if texting is not allowed or if the SIM (phone number) has been changed
* System should look for open WiFi APs to communicate.
* Accumulate and store location over time and allow sending the track once an viable internet connection is found.
* Track new SIM (phonenumbers) to enable tracking of a potential thief / finder of the phone.
Find the project source and download the alpha at: