While Apple has already offered factory-unlock iPhone 4S in some countries, there are still many iPhone users waiting for an unlock solution that allows them to use SIM card from any carriers.

Not long ago, @musclenerd from the iPhone Dev team has announced on Twitter that the team is working on a promising unlock solution for iPhone 4S. The odd part, however, is the upcoming unlock solution will only work for iPhone 4S, the latest generation of iPhone. This may suggest the unlock solution depends on a hardware exploit which only found on iPhone 4S.

As you need to first jailbreak the device before applying the unlock, it looks like the team will also release a jailbreak solution together with the unlock solution for iPhone 4S.

Unlock

For iPhone 4 User on Newer Baseband

This may sound a bad news for iPhone 4 users who have accidentally upgraded to the newer baseband. You may need to wait a bit longer before the team discovers other solutions for the unlock.

Presently, UltraSn0w for iOS 5 supports the following basebands on the iPhone 3GS including 4.26.08, 05.11.07, 05.12.01, 05.13.04, and 06.15.00. The 01.59.00 baseband is also supported on the iPhone 4. Therefore, in case you want to upgrade to iOS 5 and keep the unlock at the same time, remember to create your own IPSW firmware file and preserve the baseband.

If you have any questions related to the iPhone unlock, feel free to leave us comment.

The original post was published on Simon Blog.