The new blacksn0w unlock for iPhone 3.1.2 firmware can enable official tethering option on iPhone 3G and 3GS. For those of you who don’t know, Internet Tethering is a process which enables you to use your iPhone as a wireless modem to share its Internet connection with a computer via USB cable or Bluetooth interface. We have already posted a complete step by step guide on how to enable Internet Tethering option on your iPhone 3G/3GS which has been jailbroken with PwnageTool 3.1.4, and unlocked with ultrasn0w running iPhone 3.1.2 firmware. The following step by step guide is for those of you who have recently jailbroken and unlocked your iPhone using blackra1n RC3 with blacksn0w.

blackra1n RC3 is by far the fastest and the most complete jailbreaking and unlocking tool for iPhone running on the latest iPhone 3.1.2 firmware. The latest RC3 version includes blacksn0w which can unlock iPhone 3G and iPhone 3GS running 05.11.07 baseband. When iPhone 3.1.x firmware was released, Apple patched the exploit that allowed iPhone users to unlock iPhone’s. As a result, many users who upgraded to the latest firmware were left locked out with 05.11.07 baseband until geohot came to the rescue. Follow the simple step-by-step guide below to jailbreak all iPhone’s (2G/3G/3GS) and iPod touches (1G/2G/3G) on firmware 3.1.2.