This post is about unlocking iPhone 3G on latest iPhone 4.0 OS Beta. The hindrance to unlock 4.0 OS was that it upgrades baseband to 05.13.03 and currently no unlock tool is available for latest baseband, but updated version of FuzzyBand tool has been released to downgrade 05.13.03 baseband of iPhone OS 4 to 04.26.08 so we can use ultrasn0w later to unlock it. Please note that the tools is for older bootloader 05.08 (5.8)...

Apple has released iPhone 4.0 OS, it is Beta release and upgrade to 4.0 firmware isn't recommended till we get an official release. Switching to latest 4.0 Beta will updated baseband to 05.13.03 and at the moment no unlock tool is available for 05.13.03 baseband. This guide will help you to downgrade from 05.13.03 baseband to 04.26.08 which is necessary to unlock your iPhone later via ultrasn0w. The task is done with FuzzyBand app which...

iPhone's recent 3.1.3 firmware update hasn't really been a success for jailbreak users, quite a lot of issues have been reported while upgrading from firmware 3.1.2. Updating to OS 3.1.3 updates baseband of your iPhone as well, it will be 05.12.01. The latest Modem Firmware 05.12.01 baseband is not downgrade-able. So if you accidentally updated your iPhone to OS 3.1.3 and you want to downgrade/revert it back to OS 3.1.2, this guide will help you...

Many users faced problems in unlocking their iPhone 3G with firmware 3.1. In order to unlock your iPhone 3G through Ultrasn0w you should have baseband version 04.26.08. If you have baseband version 05.11.07 then you won't be able to unlock your iPhone 3G with firmware 3.1 as this version of baseband doesn't allow your iPhone 3G from getting unlocked via Ultrasn0w. Good news you can still unlock your iPhone 3G through Ultrasn0w but before that...