The iPhone Dev Team have released a new version of Redsn0w, their popular jailbreak tool, for iOS 4 GM. This release supports iPhone 3G and iPod Touch 2G, and gives you the option to enable multitasking and homescreen wallpapers (these devices do not have this feature, natively). This release is for Mac users only.

This release is still only meant for developers, but a lot of folks were able to get there hands on the GM build of iOS 4, as you no longer require your device to be registered with a iPhone Dev account to install it. Redsn0w will not “hacktivate” your device. You will need to install the beta of iTunes 9.2, to install iOS 4 GM. This will be useless to most, as there is nothing in Cydia that works on iOS 4 yet. Also, if you rely on your iPhone being unlocked, stay away from this. iOS 4 comes with a baseband update, that does not have an unlock yet.

Before jailbreaking, your iPhone 3G or iPod Touch 2G will look something like this:

To get started, download Redsn0w 0.9.5b5-1 here, and unzip the package. Connect your device to your computer. Once iTunes has done it’s thing, open Redsn0w. iTunes will close automatically, this is normal.

Click browse, and navigate to your iOS 4 GM firmware. For iPhone 3G, it will be iPhone1,2_4.0_8A293_Restore.ipsw. For iPod Touch 2G, it will be iPod2,1_4.0_8A293_Restore.ipsw.

Redsn0w will then process the firmware, to make sure you’ve got one compatible with this release. Click next.

Redsn0w will then download the proper patches and get ready to jailbreak your device.

Once that’s done, you’ll be given some options. You will want to install Cydia, and you’ll most likely want to enable multitasking and wallpapers, but be warned that this really slows down the user experience on these devices. If you have custom boot screens, you can add them here. Click next, when you’ve made your choices.

Resn0w will now ask you to turn off your device, but keep it connected to your computer.

Now follow the steps to put your device in DFU mode, so that Redsn0w can communicate with it, for the jailbreak. This can be tricky, so make sure you follow the directions exactly. Redsn0w will let you know if you screw it up, and give you another chance.

If you’ve done this correctly, Redsn0w will take over and you can let go of the Home button (usually with around 20 seconds left). Redsn0w is now performing the jailbreak on your device.

Once this is done, Redsn0w will say “Finished!”, and the rest takes place on your device. Your device will reboot when it’s all done.

Your device is now jailbroken with Cydia installed, multitasking enabled, and homescreen wallpapers enabled.

Again, we should say that this is just to show you that iOS 4 is jailbroken. There is nothing in Cydia working yet, for this firmware. We will probably start to see some Cydia updates after the official release of iOS 4, but most likely, it will be after iPhone 4 is release, on June 24th.