How to Unlock iPhone 4.3.2 with UltraSn0w [Tutorial]

The iPhone Dev Team has updated the UltraSn0w unlock tool with support for iOS 4.3.2. You can use PwnageTool to jailbreak your iPhone and preserve your baseband for the latest UltraSn0w unlock.
The latest release of UltraSn0w does not support new basebands, it only fixes compatibility issues with already-unlocked iPhones. In this tutorial, we’ll show you how to install the latest version of UltraSn0w to unlock your iPhone running iOS 4.3.2.
Compatible basebands:
01.59.00 / 04.26.08 / 05.11.07 / 05.12.01 / 05.13.04 / 06.15.00
Incompatible basebands:
02.10.04 / 03.10.01 / 04.10.01 / 05.14.02 / 05.15.04 / 05.16.02
iPhone 3GS owners with 6.15.00 basebands must be jailbroken on iOS 4.1 or 4.2.1. You can use RedSn0w or PwnageTool. There is a possibility that your iPhone’s GPS could be affected from the unlock.
Step 1: Open Cydia and navigate to “Manage Sources.”

Step 2: Add the following repo: “http://repo666.ultrasn0w.com“

Step 3: After you’ve added the repo, search for “ultrasn0w 1.2.2” in Cydia and install. (Make sure to double check that your baseband is compatible before installing.)

Step 4: Restart your iPhone and your device should be unlocked for operation on any compatible carrier.
Congrats, your iPhone is now unlocked on iOS 4.3.2!