From the DevTeam:
QuickPwn is not a replacement for PwnageTool, they are different tools and provide different features, QuickPwn is for quickly pwning a device, whereas PwnageTool is designed to custom build and tailor the ipsw production process, both tools will be actively developed in the future.
To use QuickPwn 1.0 Mac OS X your device should be running 2.0.2, if it isn’t then you can upgrade it to 2.0.2 using iTunes and then use the QuickPwn tool, we repeat, it’ll only work on version 2.0.2 of the iPhone or iPod touch firmware.
If you don’t want specific things to happen such as baseband updates then PwnageTool should be used to create a custom .ipsw with your specifics.
QuickPwn for Mac can be downloaded from here (Bittorent) or from our iPhone Downloads section.