Earlier this week, Apple released their highly anticipated version 4.0 of their iOS for their iPhone, iPad and iPod touch devices. This of course was a major upgrade that fans have been eagerly waiting for. Today, the infamous iPhone Dev Team has finally rolled out PwnageTool 4.0, the first iOS 4.0 jailbreak tool available.

Hopefully anyone that used previous versions of Pwnage Tool to unlock their devices remembered not to go ahead with the iOS 4 update, as this could have caused serious problems. Having said that, PwnageTool 4.0 has now been released and is ready to use for those wanting to update to iOS 4.0 on their jailbroken devices.

Since this is the first iOS 4.0 jailbreak tool to hit the market, you need to be careful before attempting to use it, as there are known problems that can occur if you don’t follow their upgrade directions to the letter.

PwnageTool 4.0 currently supports only iPhone 3G S models that came with an old bootrom that have already been jailbroken in the past. Trying to use it with iPhone 3G starts to get a bit more complicated. If you have an iPhone 3G that has not been jailbroken, they recommend that you restore to a custom ipsw file created by PwnageTool 4.0 via DFU mode.

If you have a jailbroken iPhone 3G running on OS 3.1.2 that wasn’t freed up by Spirit, you can also use the same method, or you can restore from recovery mode. But if it’s a jailbroken iPhone 3G on OS 3.1.3, it could fail during the upgrade, so it’s advised to restore using DFU mode. It is important that you use PwnageTool when entering DFU mode. For the 2G iPod Touch’s that are not MC models and have been jailbroken with a different tool than Spirit, they can be restored using recovery mode. Currently, the original iPhone and all other iPod Touch models are not supported in this version of PwnageTool.