Before you update here are some important things you should read first.

1.  iPhone 3G users:  If you want to unlock your iPhone 3G, do not upgrade to firmware 2.2.1 through iTunes, you must use a custom firmware through PwnageTool (only available to MAC users).

2. Firmware 2.2.1 permanently upgrades the iPhone 3G’s baseband to 02.30.03 and yellowsn0w unlock will not work with this baseband (so you won’t have an unlock if you upgrade your baseband).  You must make a custom firmware with baseband 02.28 using PwnageTool.

3.  If you’re using MAC 105.6 you won’t be able to get into DFU Mode but here is how you can do this:

1. You will need an account with ADC (Apple Developer Connection) this is free and takes a few minutes to sign up, you should read the terms and conditions carefully and you should only sign up if you are thinking of developing applications in the future – http://developer.apple.com/mac/
2. Download the disk image “IOUSBFamily Log release for Mac OS X 10.5.5 Build 9F33” (yes, that is a “5” in 10.5.5 – this is a developer debug package of the USB kernel extension).
3. Install IOUSBFamily-315.4.1.pkg from within the disk image
4. Reboot your system!

iPhone 3G locked users

If you don’t ever want to unlock your iPhone 3G then just update to firmware 2.2.1 through iTunes and jailbreak.

iPhone 2G users

Just update to firmware 2.2.1 through iTunes and  jailbreak.

iPod Touch 1G users

Update to firmware 2.2.1 through iTunes and run QuickPWN to jailbreak.

iPod Touch 2G users

There is no jailbreak available yet, the iPhone Dev Team is working on redsn0w.

Download QuickPwn 2.2.5 Mac

Click here to download QuickPwn 2.2.5 for Mac

Download QuickPwn 2.2.5 Windows

Click here to download QuickPwn 2.2.5 version 2 for Windows (This is the official Windows download)

Download PwnageTool 2.2.5 Mac

Click here to download PwnageTool 2.2.5 for Mac

Related posts:

1. *Unofficial* Jailbreak Firmware 2.2.1 (Windows)
2. Jailbreak iPhone OS 3.0 Beta 4 [Official Unofficial Release]!
3. Jailbreak iPhone 3.1.2