IOS 5.1.1 can be jailbreak so it can be unlocked with R-SIM III
#UPDATE May 26th,
Since IOS 5.1.1 Jailbreak released, The "CommCenter Patch" has been updated to be compatible with IOS 5.1.1 , now all Sprint/Verizon iphone 4S can unlocked successfully with our R-SIM III
How to use :
1. Jailbreak your iPhone 4S (google to find the info if you don't know how to do that)
2. Turn your iphone 4S on without any SIM card inserted.
3. Open WIFI, Run Cydia-> Source -> Manage -> Edit -> Add -> Add Cydia Source -> input “, and install this “CommCenter * patch”.
4. Add another Cydia Source “ and install “iPhone4S Network Package”, Click on "reboot your iphone 4S".
5. Put R-SIM III together your own SIM card into your iphone 4S, Settings > Phone > SIM Applications, choose US Spr or US VER, and patiently wait for 2-3 minutes, it is done