This is a big news for iPhone 4S and iPhone 4 users. Earlier, a Chinese iPhone hacker Loktar_Sun has released a solution for unlocking a jailbroken iPhone using Sam Bingner’s SAM (Subscriber Artificial Module) package. This SAM unlock method should work with all baseband versions.
I’m not able to test the method on my iPhone 4S as it’s a factory-unlocked version. However, the method has been verified on U.S. carriers by the iPhone Dev team member musclenerd as well as another iPhone blogger.