Say you are at your gym and put your G1 in a locker. You set the accelerometer alarm. Someone breaks in the locker and picks up your G1. The movement of the G1 sets off the alarm sequence. After 10 seconds (or user defined time) an alarm goes off at full volume, maybe with a voice announcement that says "Theft in progress, you have 10 seconds to enter your code." If you enter the code, the alarm ceases. Of course if you enter the code within the user defined time, the alarm is deactivated. If you don't enter the right code after the sequence is started, the alarm and voice alert stays on, and a GPS locater function is activated. Or the application would allow you to skip the alarm feature but keep the GPS locater function, for possible recovery of your G1. If it is a bonefide theft, maybe there could be a data wipe feature?
Just an idea.