My replacement iPhone 3gs was delivered and I am glad it was. Only problem is I would not be able jailbreak even if I wanted to. Here are the reasons below.
Firmware is 3.1.3
Model number is MB718LL
Modem firmware is 05.12.01
Since this phone has never had cydia installed on 3.1.2 I dont have a possibility of downgrading.2
So as you can see this iPhone 3gs came with the ability to not be able to jailbreak it. Thats fine I already have my iPod touch 2g 16 gig jailbroken. So I dont really care about doing that with my iPhone anyways.