Halo3isapro
How to Jailbreak and Hacktiver in a way Untethered your iPhone 3GS (New Bootrom) and your iPhone 4 under Firmware 4.2.1! Download all the necessary software: Firmware 4.2.1 of iPhone 3GS:
OR Firmware 4.2.1 of iPhone 4: http://tinyurl.com/2vqof7q
RedSn0w 0.9.6b6 Windows : http://ipodtouchisapro.net/jbpourlesnuls/jblogiciels/redsn0w0.9.6b6.exe
Greenpois0n RC6: http://greenpois0n.com/
Another link for Firmwares: http://www.felixbruns.de/iPod/firmware/
NOTE 1: If you have an iPhone 3GS (Old Bootrom), you don’t need to do the Greenpois0n step, because you are already Untethered NOTE 2: Please put RedSn0w0.9.6b6.exe in Windows 98 Compatibility! Redirection to other videos: Untethered Jailbreak with Greenpois0n only: http://www.youtube.com/watch?v=ZJcUSvpLNb4
Upgrade your iPhone 4 to Firmware 4.2.1 while preserving its Baseband: http://www.youtube.com/watch?v=29YypCW7eNc
Sincerely, iPodTouchisapro
http://www.ipodtouchisapro.com/
Source Cydia : http://apt.ipodtouchisapro.org/
Twitter : http://twitter.com/#!/iPodTouchisapro/
WikiTiAP : http://wikitiap.com/index.php?title=Accueil
JailbreakForDummers: http://jailbreakpourlesnuls.com/ .