Apple N Berry has released the new Gevey Ultra S GSM that can unlock iPhone 4S on iOS 5.1 and iOS 5.1.1 without requiring any jailbreak.
Keep in mind that Gevey Sim owners earlier claimed that their latest Sim card can unlock any firmware on any baseband including the 4.11.08 and 4.12.01 on iOS 5.1. Later it reveled that they were using the same exploit that was made by the developer of SAM unlock. Point to be noted that SAM unlock was distributed free to the public in the form of a Cydia package while Gevey Ultra was using the same exploit at a price $49.99. Apple N Berry later recalled the sim cards and started refunding the users after SAM was patched by Apple. There they kind of lost trust but anyways.
Hope they are not using any server side exploit this time and are offering Gevey Ultra S as a permanent unlock solution. It can unlock GSM iPhone 4S on iOS 5.0, 5.0.1, 5.1 and 5.1.1 on basebands including 1.0.11, 1.013, 1.0.14, 2.0.10 and 2.0.12. The company claims there is no need to dial International Emergency Number 112 plus no jailbreak is required.
The Gevey Ultra S for iPhone 4S GSM model is available for $39.99 from ApplenBerry.