This is the low down on our tools for use with the 2.2.1 firmare from Apple, read the whole post in full before attempting anything.

1. GOLDEN RULE: If you have a 3G iPhone running 2.2 firmware and
   you want to keep your ability to use yellowns0w (or the option to use
   it in the future) do NOT use QuickPwn, and do not use the official ipsw or the iTunes update process without using PwnageTool.
2. Yellowsn0w will NOT work with the baseband version (02.30.03)
   that is present in the recent 2.2.1 update  - you will need to create a
   custom ipsw that will allow you to update safely without affecting the
   baseband.
3. Please read all parts of this post before downloading and using these tools.
4. Read items 1, 2 and 3 again and again.
5. At the bottom of this post are the bittorrent files for the latest versions of PwnageTool and QuickPwn.
6. These apps are suitable for the recent 2.2.1 release.
7. The Yellowsn0w version has been updated to 0.9.7. Yellowsn0w is available from Cydia or Installer - this version allows compatibility with pwned 2.2.1 system (not baseband) - again - remember 0.9.7 yellowsn0w DOES NOT WORK WITH 2.2.1 (02.30.03) directly - you need to be running a ‘pwned’ version of 2.2.1 which doesn’t upgrade the baseband.
8. Users of OS X 10.5.6 will be unable to use DFU mode correctly,
   please see the note towards the end of this post to easily fix this
   issue.

Baseband 101

The ‘baseband’ is the generic name
given to the internal components of the iPhone that handle the phone
calls and Internet access. This ‘baseband’ is a tiny and unique
independent computer system that runs inside your iPhone, it is
separate to the main system that handles the applications (such as
email and google maps) and it talks to the main part of the phone over
an internal communications network. Think of it like a cable modem or
other peripheral that is attached to your home PC that needs occasional
updates. When a software update is released and presented to you within
iTunes the baseband is sometimes updated (to fix bugs or add new
features). The 2.2.1 update for the iPhone 3G contains such an update,
so running the vanilla updater straight away with iTunes will reprogram
and update the baseband. This could be bad for certain people,
depending on your ultimate aim.

SIM Free/SP Unlocked/Factory Unlocked iPhone 3G

This applies if you bought your iPhone 3G for $$$$$$$. This
model of iPhone 3G doesn’t have an Service Provider lock (aka factory
unlocked) and you are able to put any SIM card into the phone and get
service. Your phone is already unlocked so you do not need to worry
about baseband updates, simply upgrade to 2.2.1 using iTunes and then
use QuickPwn to Pwn and Jailbreak. This will add Cydia and Installer
too.

Locked iPhone 3G - Preserve Baseband

This
applies if you have a locked iPhone 3G and you wish to update to 2.2.1
but preserve the iPhone’s current baseband software. Preserving the
baseband will ensure that you can still use “yellowsn0w” the iPhone 3G
unlock application. To upgrade your phone to 2.2.1 and preserve the
state of the baseband you need to create a custom .ipsw with
PwnageTool. This custom .ipsw will not contain the baseband update but
of course will still allow all the cool new stuff from 2.2.1

There
are plenty of tutorials about this process on the web, but PwnageTool
contains intuitive graphics and easy to follow prompts that should have
you up and running in no time at all. Please note: PwnageTool is only
available for Mac OS X.

Locked iPhone 3G

If you are using your iPhone with one carrier and have no interest
in the possibility of an iPhone 3G unlock in the near future then just
restore or upgrade to 2.2.1 using iTunes and use QuickPwn to Jailbreak
and add Cydia and Installer.

iPhone 2G (1st Generation)

Update or Restore your iPhone 2G with iTunes then run QuickPwn to do
the magic, ‘nuff said, you don’t need to worry about anything.

iPod Touch 1G (Original iPod Touch)

Update to 2.2.1 with iTunes and run QuickPwn.

iPod Touch 2G (New iPod Touch)

Sorry, no support at this time, but Redsn0w is being developed.

Fixing DFU mode on 10.5.6

As noted previously OS X 10.5.6 introduced a bug that affected the
use of DFU mode. There have been previously published hacks and
techniques to fix this, but there is another method that can be used to
easily restore functionality.

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!

Official Bittorrent Releases -

• PwnageTool 2.2.5 for Mac OSX is here SHA1 Sum - 8fe2f20c00f48b37d8262d6872a12166c6e165ba
• QuickPwn 2.2.5 for Mac OSX is here SHA1 Sum - 2f1353242ef10dc408e95786643e497fcd04e4ea

• QuickPwn 2.2.5 for Windows is coming soon!

Unofficial Mirrors

The following links are
unofficial download mirrors, you download these at your own risk, we
accept no responsibility if your computer explodes or if it becomes
part of a NASA attacking botnet or even worse if your hands fall off
mid-way during the use of these archives. We do not check these links
or archives. Always check the published SHA1 sums. We would prefer that
you downloaded the official bittorrent release that is linked above,
but you are welcome to try these if you really must. Mirror owners
should email direct links only to blog@iphone-dev.org , please don’t place mirrors in the comments as they will be deleted.

Mac PwnageTool

• http://iphone-dev.fgv6.net/PwnageTool_2.2.5.dmg
• http://iphone.schwarzmetall.cn/PwnageTool_2.2.5.dmg
• http://rabstalk.bplaced.net/mirrors/PwnageTool_2.2.5.dmg
• http://jmcoon.net/PwnageTool_2.2.5.dmg
• http://downloads2.ipod.backshot.eu/PwnageTool_2.2.5.dmg
• http://www.iphone-storage.de/PwnageTool_2.2.5.dmg
• http://miphone.ca/iphone-dev/PwnageTool_2.2.5.dmg

Mac QuickPwn

• http://iphone-dev.fgv6.net/QuickPwn_2.2.5.dmg
• http://iphone.schwarzmetall.cn/QuickPwn_2.2.5.dmg
• http://rabstalk.bplaced.net/mirrors/QuickPwn_2.2.5.dmg
• http://jmcoon.net/QuickPwn_2.2.5.dmg
• http://www.iphone-storage.de/QuickPwn_2.2.5.dmg
• http://downloads2.ipod.backshot.eu/QuickPwn_2.2.5.dmg
• http://miphone.ca/iphone-dev/QuickPwn_2.2.5.dmg

Windows QuickPwn

[via iPhoneDevTeam]