Instructions on how to untether your jailbreak for those who previously had a tethered jailbreak of iOS 6.x for their iPhone 4, iPhone 3GS, or iPod Touch 4G.
Apple support technicians will reportedly start using a new remote diagnostic tool that can run tests on your device and send the results back to Apple.
Instructions on how to unlock the iPhone 4, iPhone 3GS, and iPhone 3G for use with any GSM cellphone carrier using UltraSn0w. This will work with the iOS 4.2.1 firmware on the 06.15.00 baseband.