The tool will not however function on an iPhone 3GS which has iPhone OS.3.1 installed. The iPod touch (second generation) is also now supported, though the most recent third edition model is not.
The developers state:
“The iPhone 3GS is now supported in PwnageTool 3.1.3, assuming the phone was pwned at 3.0 or 3.0.1 – PwnageTool does not support the 3GS out of the box. If your iPhone 3GS has 3.1 preinstalled and is not Pwned then there is no tested jailbreak solution at the moment.”
Jailbreaking an iPhone is a complex task that should not be attempted by anyone who has not fully read and understood the extensive instructions provided on the Dev-Teams blog.