WaveSecure: Anti Theft Application For Nokia S60v3 and v2, is an aplication that will let you know if your phone is stolen as it sends you a message to a selular number as you set on the application once the simcard on the phone is replaced with another one. And such, you can't set the selular number that will receive the message to the same number that you use on the phone, cuz it means 90% you won't receive the message but the person who stole your phone.
Here are the download links:
WaveSecure Antitheft S60v2.sis
WaveSecure Antitheft S60v5 v3 Unsigned (OS9x).rar