DevTeam recently released new version of redsn0w to jailbreak iOS 4.1. New RedSn0w 0.9.6 b1 supports iOS 4.0 and iOS 4.1 running on iPhone 3G or iPod touch 2G.
There is only Mac OS X x86 version, that you can download here.
Select your stock 4.1 or 4.0 ipsw (you’ve already used this to update your device to 4.1 or 4.0)
Select “Install Cydia” and any of the other options shown above, then click “Next”. Use DFU mode to install the jailbreak.
As usual DevTeam reminds us: IF YOU USE THE ULTRASN0W UNLOCK, PLEASE WAIT FOR PWNAGETOOL TO SUPPORT 4.1. DO NOT USE REDSN0W
That’s because to use redsn0w at 4.1, you need to already have updated to official 4.1 from Apple. If you do that, you lose the ultrasn0w unlock (possibly forever).
Have you already updated your device to the version iOS4 and want to unlock your 3GS? Firstly there was Redsn0w, now PwnageTool is available, which can easily help you. Here is a simple and easy tutorial for jailbreaking iPhone 3GS (old bootrom). Warning: this is not an official release and therefore may be some bugs that can destroy your device or delete some important information. So be careful while using it!
DevTeam says that 2.2 update SHOULD NOT be applied using iTunes if you want the chance of a soft-unlock in the near future. Use new version of PwnageTool (not avaliable yet, but will be soon).
Some fact:
The 2.2 firmware for 3G contains a baseband update for the 3G iPhone
The 2.2 firmware for 2G (1st gen iPhones) doesn’t contain a baseband update and the baseband is still at 04.05.04
Pwnage technique (and therefore the Jailbreak) isn’t affected, but PwnageTool and QuickPwn do not support this release as yet, so DO NOT install 2.2 using iTunes as you will lose your jailbreak
If you apply this update and you previously relied on PwnageTool or QuickPwn to activate your phone, it may become temporarily deactivated and unusable (until we release the new version of PwnageTool or QuickPwn).
PwnageTool and QuickPwn updates will be released as soon as possible that will allow a safe update path to 2.2 the release of these updates is inevitable but not imminent, we are creating the modifications right now and we need to put the new software through the usual testing process.
If you apply this update and you have third-party (non AppStore) applications from Cydia and Installer that you rely on they will stop working.
2G (1st gen) iPhone users who cannot wait for the new PwnageTool or QuickPwn can safely “Update” to 2.2 using iTunes, this will preserve the existing activation. However “restoring” to 2.2 using iTunes will return the iPhone to the unactivated state. If you are in any doubt just wait. NB: This works for 2G ONLY.
The use of SIM-Proxies (small circuit boards/chips that sit underneath the SIM card) to provide GSM/UMTS service on your locked iPhone 3G: early reports suggest that the 2.2 update disables the functionality of these devices.