This post will show you how to Unlock iPhone 3G running 3.1 firmware using Ultrasn0w which is a utility on Cydia that allows iPhone 3G users to unlock their devices, which means they can use it with any Carrier.

  • Jailbreak iPhone 3G 3.1 Firmware
  • Connect to a WiFi network so you can use software repo’s in Cydia
  • Open Cydia, it may require restart for the first time
  • Go to the Manage tab on the bottom, then Sources
  • Now hit Edit, then hit ‘+’.
  • Now type in the following: http://repo666.ultrasn0w.com/ then hit Done.
  • Now go to the Search tab and search for Ultrasn0w
  • Install it, then restart your iPhone with your SIM Card in the device (if not working, re-insert your SIM card.
  • Enjoy your Unlocked iPhone 3G!