After you’re done with Jailbreaking your iPhone with Firmware 3.1, its time to Unlock it, so that it can be used on any carrier Worldwide. In order to do so, follow the following steps carefully after Jailbreaking:

• Start “Cydia” on your iPhone.
• Touch on “Manage” tab on the bottom.
• Tap on Sources
• Tap on “Edit” and then on “Add”. You will be prompted to enter a url source. Type “http://repo666.ultrasn0w.com” and touch on “Add Source”.
• Cydia will now automatically complete the installation. After that, tap on “Return to Cydia”
• Search for Ultrasn0w (Its sn0w, with the digit zero)
• Download and Install it, like previously done.
• Restart your iPhone and now you’re good to go

Enjoy your Unlocked device on any carrier around the World.