Update : New Links Added
There is a simple way to update to iOS 5.1 without basebande update . easy unlock and jailbreak . Its a Tethered jailbreak for iPhone 4 and iPhone 3Gs. if you get iTunes 16XX error use iREB.
1 . Custom firmware for Device :
NOTE 1 : This customs is not jailbroken.
2- iREB R5 (mac users Should use DFU tab Option in PwnageTool and follow instrument )
1. Connect your phone with PC and switch off
2. Open iREB R5 and follow olders
3-After that open itunes and press “Shift + Restore” and choose custom firmware 5.0.1 (Alt + Restore for Mac Users)
it will finish very quickly
4- Jailbreak iPhone with Redsn0w 0.9.10b6
5- For iPhone 3Gs or iPhone 4 with 1.59.00 baseband use this How to Unlock iPhone 4 , 3Gs on iOS 5.0.1 . if you have iPhone 4 with 2.10, 3.10.1, 4.10, 4.10.1 baseband read this How to Unlock iPhone 4 using GEVEY and Gevey Ultra SIM on iOS 5.0.1
WARNING: If you depend on UltraSn0w unlock, you must STAY AWAY from RedSn0w and stock iOS 5.01