Comex released the iOS 4 jailbreak (which all iDevices can be jailbroken), and now users can unlock their iPhones using Ultrasn0w. Before launching Cydia and installing Ultrasn0w, continue reading below for requirements.

The latest version of Ultrasn0w unlocks the iPhone 3G and 3GS running iOS 3.1.2 – 4.0.1, but DOES NOT unlock the iPhone 4. As mentioned earlier today, MuscleNerd and Planetbeing from the iPhone Dev-Team are still testing to make sure it’s flawless. Although I’m sure a release will be available within the next couple days, we’ll keep you updated.

This guide will show you how to unlock iPhone 3G or iPhone 3GS running iOS 4 using Ultran0w.

1. Sync your iDevice with iTunes to back-up all your important data including settings, apps, music, contacts and photos.

2. Jailbreak your iDevice using jailbreakme.com (read our how to here)

3. Launch “Cydia” on your iDevice.

4. Typically, the Ultrasn0w repo is included with Cydia. If not, tap the “Manage” tab located on the bottom tab bar.

5. Tap “Sources”, “Edit”, then “Add”. You’ll be prompted to add URL source. Type “http://repo666.ultrasn0w.com” and tap “Add Source”.

6. Cydia automatically refreshes and updates sources.

7. After Cydia is done refreshing sources. Tap the “Search” tab on the bottom tab bar and search for Ultrasn0w. Once Ultrasn0w appears, tap and you should see version “0.93″. Ultrasn0w is a software unlock for your iDevice, so you can use it with any carrier by simply inserting the SIM card.

iPhone DevTeam’s 3G and 3GS software unlock, now with added PwnApple. Compatible with basebands o4.26.08, 05.11.07, 05.12.01 and 05.13.04! Thanks to @sherif_hasim and @ 0ranav for contributing baseband crashes.

8. Restart your iDevice and done! Your iDevice should now be fully unlocked.

Don’t forget to check out our HOW TO section for the latest tips and tricks!

Note: We are not responsible for any damage or loss of data on your iDevice. Use at your own risk.