That's why I suggested to send "last known" position, instead of trying to get a GPS fix. If somebody stole it they are almost certain to use the Map at some point of time... and would wait the GPS to have fix. Then the app can just read the coordinates data and possibly time stamp with it. Then it would not draw the thief attention he's being spied/watched. If the "call home" applet reports every few minutes, you could even draw the router the thief was driving, assuming he had active internet connection.