Dutch company JavaMania has released a program for GSM mobile phones called SimWatcher, what it does is sends out an SMS message when someone replaces the SIM card in the phone. If your handset is stolen this is probably your only chance to find out the number of the thief to maybe get your phone back, so don’t set the SMS message to your own phone or you won’t have any luck.
SimWatcher is easily installable on almost every type of GSM phone, you can download the SimWatcherS60.sis using your phones WAP browser, or send it from your desktop to your phone via Bluetooth or IRDA.
The application runs in the background of your handset and will cost you €10. This software won’t guarantee you get your phone back, but if you reason with the thief he may part out with it for a reward, or you can report your IMEI number to your phone company to have it banned from ever receiving service again.