Ultrasn0w 1.2.3 has been released today to make thecompatible with .3 on and 3GS, running on the old baseband.
Supported basebands: 01.59.00 / 04.26.08 / 05.11.07 / 05.12.01 / 05.13.04 / 06.15.00
Unsupported basebands : 02.10.04 / 03.10.01 / 04.10.01 / 05.14.02 / 05.15.04 / 05.16.02
Note: Updatingbaseband to ’s 06.15.00 might result in loss of GPS functionality.
Step 1: First up, you will have to jailbreak your iPhone 4 or 3GS on.3 and preserve the old baseband using either PwnageTool on Mac, or Sn0wbreeze on Windows. Instructions on how to jailbreak 4.3.3 using PwnageTool can be found here, and for Sn0wbreeze can be found here.
Step 2: Once you are done with the jailbreak, you can now unlock your iPhone on the supported basebands using Ultrasn0w 1.2.3 from. To do this:
Step 3: Go to Manage->Sources Step 4: Now tap on “Edit”, then tap on “Add” and Enter the following repo http://repo666.ultrasn0w.com Step 5: Now tap on “Add Source” then tap on Done. Step 6: Search for “ultrasn0w ” in Cydia and install this application. This app will automatically unlock your iPhone so that you can use it with any carrier.
Step 7: Now simply restart your iPhone and you should now have a fully unlocked iPhone 4 or 3GS/3G, running iOS 4.3.3.
Step 8: Now press the Home button then power off and power on the iPhone. You do this by holding down the power button for 3 seconds then moving the power slider that appears to the right. Press the power button again to turn on the phone. You should now be able to insert the SIM of your choice!
***THANKS: A big thank you to all the members of the iPhone Dev-Team for all their hard work! It is much appreciated by all.