Update : The latest version of Redsn0w (Windows) can enable that tricky DFU mode on Windows! Macs can use the Pwnage tool to create the custom firmware itself…
Warning : This isn’t for the faint of heart. I did not post a detailed writeup cos’ DFU mode is kinda tricky on this one. If you know what this is and what it means, go ahead and try this. All others, please wait while other Windows users verify this.

The links are all interchangeable and you have all the mirrors you can ever think …

CAUTION : iOS 4 jailbreak is way complicated unlike other jailbreaks. Please proceed with caution.
Requirements :

Jailbroken iPhone 3GS with older bootrom.
You haven’t used Spirit jailbreak before (for untethered jailbreak).
You have Windows (PC). For Mac, try Pwnage instead.
Please read the above requirements again.

More info about these custom firmware files :

[UPDATE] : You need to download files from either step 1a or 1b depending on your baseband preference. Both are unlockable, so I would go with step 1b which is the latest baseband which supposedly does better with the battery. step 1b …

UPDATE : 3.1.3 Custom Firmware for iPhone 3G and 3GS now available!
The Dev Team did it again in style by releasing Pwnage tool for 3.1.3 iPhone Firmware. 3.1.3 Firmware from Apple is not a noteworthy upgrade and it is suggested you skip it! Few bug fixes, battery fixes, unlock-mess ups are everything Apple has to offer with 3.1.3 firmware! Some of us just like the higher software version and there is nothing stopping us from trying it, eh?
3GS users should proceed cautiously. No kidding! Drop a comment if you have …

The much awaited Pwnage tool 3.1.3 is finally ready for download. Thanks Dev Team, now we can successfully jailbreak iPhone 3GS for  3.1.
Download Pwnage Tool 3.1.3 from Rapidshare mirror here if you have a Mac. No Pwnage tool exists for Windows platforms.
Custom 3.1 firmware links below for the following iPhone models :

iPhone 2G 3.1 (Original iPhone)
iPhone 3G 3.1
iPhone 3GS 3.1

Redsn0w is a revolutionary way to jailbreak, activate, unlock an array of Apple’s devices based on iPhone 3.0 firmware. Devices like iPhone 2G, iPhone 3G, iPhone 3GS, iPod Touch 1G/2G can easily be jailbroken, activated and unlocked (iPhone 2G – Automatic, iPhone 3G – Manually via Cydia & Ultrasn0w).
If you don’t want to go through the following steps and you just want the real deal, follow this guide rather wherein you can download the custom firmware file which should do the job for you!
The tool itself is so neatly packaged …

Note : If you are planning on using Gevey SIM, please take a quick peek at this marathon race into chasing the mystery behind Pwned iPhone 3G 2.2 and Gevey SIM issues.
This custom pwned firmware version 2.2 has the older Baseband, Factory default logos (No Pwnapple at boot!) , Pre-activated for non-ATT users, Root Partition size 1000 MB, Cydia and Installer as a bonus to make life simple!

Recommended Steps :
Pwn your iPhone 3G when at firmware version 2.1 using QuickPwn 2.2 either using Windows or Mac(STRICTLY REQUIRED)
Now, download this Custom …

These are the most essential files for Jailbreaking/Unlocking iPhone 2.0 and since they are scattered all around the place, I thought of providing a single link which would definitely ease the process.
DOWNLOAD THE COMMON FILE
I am working on a video as well as detailed Pwnage 2.0.1 guide for the noobs. Pwnage is rock solid but some surprises here and there surface every now and then.

This is an effort to provide a quick and easy access to free stuff offered from iTunes Store. All you have to do is click here to launch the free selections offered every week. The URL launches iTunes with the selection.

The best part being access to free downloads right on your iPhone / iPod Touch. Just click the link and you can access the free downloads on your device! You don’t have to pay to experience OTA downloads from iTunes store. Some songs offered for free may be featured on …