HOW TO UNLOCK AN IPHONE
How to Unlock an iPhone
June 10th, 2008To do this, you need to first check which version of firmware you have by dialing *3001#12345#* on the emergency dial screen. If it shows 04.01.13_G, you’re ready to go. If not, you need to either downgrade/upgrade your firmware to v1.1.1. by following the instructions here http://iphone.unlock.no/#recovery-restore-mode.
Jailbreak
1. Now that you’re on v1.1.1, you need to jailbreak—make your phone able to install third-party applications. Make sure your SIM card’s PIN is turned off.
2. Slide to open the emergency dial screen and dial *#307# and hit Call.
3. When it rings, hit the X button to delete the numbers and type 0 and Call again. When it rings, press Answer.
4. Then press Hold. When the phone rings again, press Decline, then it should show the normal dial screen now.
5. Press Contacts from the bar at the bottom
6. You now have to create a new contact by pressing + sign.
a. In First Last: Unlock
b. Add New URL: prefs://1F and click Save.
c. Again, Add New URL: http://www.jailbreakme.com and then Save.
7. Now click on home page prefs://1F button and it will take you to Settings. Connect yourself to the internet using a wifi connection.
8. Restart your iPhone.
9. Now, repeat from step 2-5.
10. Now choose home http://www.jailbreakme.com button and it will open your Safari browser.
11. Scroll down to the bottom and choose Install AppSnapp.
12. Safari will close and the iPhone will restart in 30 seconds.
Unlock
1. Open Installer.app, and click Sources and then Edit.
2. Click Add and type http://i.unlock.no and click OK
3. When it finishes loading, click Done.
4. Close the Installer and reopen it.
5. Click Install button at the bottom and scroll to find Unlocking Tools.
6. Choose AnySIM and click Install
7. You should now the AnySIM icon on your iPhone home screen. Click on it.
8. Slide to Unlock.
9. Click OK. Unlock My iPhone.
10. Your iPhone is now unlocked.
Sources: Lifehacker.com, Modmyifone.com, iphone.unlock.no