After a long wait the Dev-Team has finally released the latest carrier unlock tool for iPhone 3G working on the latest 3.0 firmware release!

The tool named ultrasn0w only works on the jailbroken iPhones. Here are the steps for jailbroking and unlocking your iPhone 3G.

1. Download redsn0w from here.

2. Fire up redsn0w and connect your iPhone 3G on the USB port.

3. Follow the onscreen instruction to enter into the DFU mode.

4. Under Options select Install Cydia. You must select this because ultrasn0w is only available in Cydia app repository.

5. Press Next and wait for a while until the jailbroken data is downloaded and installed on your iPhone 3G.

6. Once it is done and your iPhone 3G is restarted, Run Cydia.

7. In Cydia goto Manage > Sources. Tap on the Edit button at the top and add the repository repo666.ultrasn0w.com. That last “o” is actually the number zero “0”! If you use the letter “o” you’ll get an error.

8. Search for ultrasn0w in Cydia and install ultrasn0w.

9. Reboot your iPhone 3G

10. Your iPhone 3G is now unlocked!

P.S: T-Mobile USA users should disable 3G before using ultrasn0w

For disabling you iPhone 3G settings go to Settings-> General-> Network and turn off 3G Mode.