Hi everyone, I have tried to understand the unlocking process from the various threads posted here, but ended up more confused I have an iphone 3GS 4.2.1 (BB 05.15.04). As I understand, i need to upgrade the BB to 6.15.00 to be able to unlock it. Firstly, to jailbreak I am looking at 2 options : redsn0w 0.9.6 beta5 (tethered) and greenpois0n (untethered). redsn0w will upgrade the baseband to an iPad BB and I will be able to run ultrasn0w to unlock the phone. (I suppose you need to save SHSH blogs for this). On the other hand, greenpois0n seems to be straightforward J/B option and also untethered (which i prefer), but won't upgrade the BB thereby not able to run ultrasn0w. Can i follow the below steps to untether J/B and unlock my phone? 1) Use redsn0w to J/B and upgrade the baseband. 2) Run greenpois0n over redsn0w to J/B again for getting an untethered jailbroken phone. 3) Run ultrasn0w to unlock the phone. I am not sure if there is a way to untethered jailbreak with redsn0w so that i don't need to use greenpois0n. Also, are there any potential issues with the above steps? Please suggest.