Unlock iPhone 4.3.2 with UltraSn0w

The iPhone Dev Team has updated the UltraSn0w.This tool is unlock tool with support for iOS 4.3.2. Then you can use PwnageTool to jailbreak your iPhone and preserve your baseband for the latest UltraSn0w unlock.
The latest version of UltraSn0w is not support new basebands, it only fixes compatibility issues with already-unlocked iPhones. In this article, we will 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!