From The Apple Wiki

Pneumonia is a application created by GreySyntax and GRMrGecko to aid in booting and preparing the iPod touch (3rd generation), as well as the iPhone 3GS and iPod touch (2nd generation) (new bootroms), for restore. This utility is a port of iBooty & Payload Pwner. This utility replaces the old method described on OpenPwn (See notes).


To use this utility you must have saved 3.1.2 SHSHs or be on 3.1.2. A Mac running OS X 10.4+ A custom 4.0+ restore with the NOR flash disabled.


This application will extract both the 3.1.2 & custom IPSW and saved your patched files in "~/Library/Application Support/Pneumonia" + stock firmware md5 sum. This allows the application to support multiple devices and prevents it from having to extract the IPSW upon every application launch.


NSPwn (Pre compiled)[dead link]

Github (Source)


Old method [Archived 2010-07-31 at the Wayback Machine]