PwnageTool

PwnageTool is an iOS jailbreak tool for Mac OS X that jailbreaks by creating a custom IPSW. You are allowed to change boot logos and add pre-installed packages to the IPSW. After an IPSW is created you can use it for restore using iTunes.

Credit
iPhone Dev Team

Version 1.0

 * Pwnage
 * Ramdisk Hack

Version 2.0

 * Pwnage 2.0
 * Pwnage

Version 4.0

 * Bootrom exploit (used by limera1n and greenpois0n)

Models Supported
Please note that the iPad 2 and the iPhone 4S are not yet supported, as there is no publicly available bootrom exploit (like Pwnage, Pwnage 2.0, limera1n) for the A5-Processor.

Versions
PwnageTool was released 3 April 2008 but largely unused until version 2.0 was released 19 July 2008. The following versions that are shown here are not beta, alpha, or in development.

Creating the Firmware
PwnageTool takes the IPSW file and patches it, creating a custom version. This enables a lot more features such as pre-installed packages, BootNeuter (iPhone software unlock), custom packages and boot logos. This method is usually less secure than the quick exploits such (redsn0w, QuickPwn, purplera1n, blackra1n, etc.).

Problems
This method does have negative aspects. The most common errors are the 16xx range of errors, which mean that the either the firmware file is corrupt or you didn't put it in the right mode (Recovery, DFU Mode). Sometimes the problems could just be a computer problem such as the memory is full or the USB port is broken. The most common error is Error 1604 which means that the firmware file is corrupted.

Windows
PwnageTool is expected to remain exclusive to Mac OS X. As of October 2009, iH8sn0w, et. al. has announced that they made a project that will bring PwnageTool's functionality to Windows, called sn0wbreeze. 

License
PwnageTool is freeware.