Iphone sim card question?

ok i have a motorola w375 with net 10 service. and i have read that net 10 (it is a prepaid phone) uses cingulars network. Also my phone has openwave for internet browser and uses a net 10 gsm sim card. I am thinking about buying an iphone that is unlocked and jailbroken and putting the sim card from the net 10 phone into the iphone (i am watching youtube videos and stuff on how to another sim card in the iphone) and i was wondering if anyone knows for sure if this is possible becase i have heard both that it will and that it won't but i just want to know a little bit more so thanks