iphoneNow, you can unlock iOS 4.0 Baseband 05.13.04 on iPhone 3G & iPhone 3GS with ultrasn0w 0.93. if you have jailbroken iPhone 3G/3GS 4.0 only then you can unlock iOS 4.0 with baseband 04.26.08 thru 05.13.04

We also posted about Unlock iOS 4 with Blacksn0w and Unlock iOS 4 on iPhone 3GS with Blacksn0w RC2 you should take a look at them! T-Mobile USA users must disable 3G before.

How to Unlock iOS 4.0 Baseband 05.13.04 on iPhone 3G/3GS

1.  Jailbreak iOS 4.0 using Redsn0w, then start Cydia and go to Manage section.

2. Click on sources > edit to add following

Repo666.ultrasn0w.com (it’s ‘0(zero)’ and not ‘o’)

3. Do search for Ultrasn0w 0.93 and click on install

4. Let Ultrasn0w 0.93 to complete unlocking

and Bingo 😉