Time: 2012-05-13 Click:
While iOS 5.1.1 may have thrown jailbreakers a curveball, unlockers using the GEVEY Ultra S GSM with their GSM iPhone 4S will be happy to know it's safe to upgrade. According to online retailer ApplenBerry's Twitter feed, the GEVEY Ultra S GSM is compatible with iOS 5.1.1.
CDMA iPhone 4S or 4 models need to be jailbroken to use the Ultra 5.1 SIM interposer. There is no jailbreak for iOS 5.1.1 currently, but the GEVEY Ultra S does support iOS 4.1 and later (through 5.1). iPhone owners should not update to iOS 5.1.1 if they would like to keep their devices jailbroken.
There are other unlocking solutions like the popular SAM unlock method, or the R-SIM interposer.