dont know about it but this is just a guess!!! okie every mobile phone has their unique license no. (like us our name)nokia for example type *#0000# or *06# a license no. will apper on the screen that correspond to that, if your phone get or transmit a signal maybe the protocol of the phone is their license no. and btw mobile company hav their own cell sites scattered her in earth or on you country that bounce signal going to the server, reciever and to your phone maybe that how it works. ive seen the series in smallville were lex tries to locate his pal who was stuck under a deep excavation the mobile company provide lex info were the signal bounce and wat specific location or area then there they start searching...hehehe just a wild guess or if your mobile phone is wap able then satellite can locate you... heheheheh