Redsn0w jailbreak courtesy of Kosovar of thephoneproject, updated June 23, 2009.

Redsn0w is a jailbreak for iphone and ipodtouch 2 similar to quickpwn for 2.x. This will not restore your iPhone. You have to restore before running the tools. The tools run on both MAC and Windows. The tool is very straightforward and easy to use. Onto the guide:

Downloads:
Install iTunes 8.2 (or use software update on the MAC).
Redsn0w Windows or redsn0w MAC or redsn0w Linux
For iPhone 2g unlock: Bootloader 3.9 and 4.6.
Appropriate firmware file. You can get all firmwares from my firmwares link.

(Note screenshots are from a PC, but they are the same as MAC)

Guide:
Step 1) Run redsn0w

Step 2) Press “Browse” and find the correct firmware for your device.  You should have downloaded it above because you should have read the needed files section!  PLEASE make sure that if you have an iPhone 3G, your firmware should start with iPhone1,2_3.0 and if you have an iPhone 2G it should start with iPhone1,1!  This is a big deal, it won’t work without the correct firmware!

Click “Open”, and redsn0w will process your firmware.  When it is done, it should say “IPSW successfully identified”.

Step 3) On the next screen you will be able to install Cydia, and I suggest you do so.  What’s the point of jailbreaking if you can’t install jailbroken apps? (rhetorical =) Note: I suggest not installing Icy. At least at the point of this writing, there seem to be conflicts having both installed and Cydia handles apps better and you will have less problems.

Just hit the next button, and you will see this:

At this point, you want to turn your phone off.  Hold the power button until you see the “slide to power off”, and do it!

The next screen wants you to follow a series of instructions that will put your phone in DFU Mode.  This will allow redsn0w to perform the jailbreak.  You need to do this correctly otherwise it won’t work. If you have any problems, see my DFU mode guide.

1. Hold down the Power (corner) button for 3 seconds
2. Without releasing the Power button, push the Home (bottom center) button for 10 seconds
3. Without releasing the Home button, release the Power button BUT KEEP holding the Home button for 30 seconds.

Once redsn0w starts doing something, you can release the home button on the third step, you don’t have to hold it down for all 30.  You’ll KNOW when it happens.

Now your phone will be doing a series of things - and in the end, you will have a jailbroken iPhone!  Please comment below with success, failure, and suggestions on the short guide.