update : iPhone 4 GSM 9B208 Added
There is a simple way to update to iOS 5.1.1 without basebande update to use Gevey sim or unlock with Ultrasn0w if you can . easy unlock and jailbreak . Its a untethered jailbreak .
Updated to Redsn0w 0.9.10b8 , can backup those priceless activation tickets
iPhone Dev Team has released RedSn0w 0.9.10b8b which is now can jailbreak iOS 5.1 and 5.1.1 tethered iPhone 3Gs , iPhone 4 , iPad , iPod 3G and iPod 4G .