Are you having an issue where the PwnageTool from the iPhone dev-team simply will not launch on your computer? For many, it just bounces in the dock for about three minutes and then does absolutely nothing (it sticks around in the dock except you will not see the open application indicator under it). This seems to be affecting primarily MacBook and MacBook Pro owners but it also is failing on some older PowerPC equipment.
It’s a pretty easy fix although.
Open ‘Activity’ Manager and show all processes (even root)
Quit the process named ‘ps’ (you will be asked for admin privileges)
You should do this while the PwnageTool is open. Also, you will need to ensure the folders \<user>\Library\iTunes\Device Support and \<user>\Library\iTunes\iTunes Software Updates exist on your machine.
To be quite honest, I’m not certain what the ‘ps’ process does and you should always take cautiou when fiddling with processes on your machines; however I have used this will no ill effects however I did restart once I finished ‘pwning’ the phone. Good luck!
EDIT (7/21): This bug has since been fixed in version 2.0.1, read here.