Once again QuickPwn has been modded to jailbreak iPhone 3.0 Beta 4. All the same rules apply like the other 3 beta jailbreaks. It will jailbreak your iPhone, iPhone 3G, or iPod Touch 1G. And it only installed Icy, not Cydia. If you’re an iPhone 3G user and dependent on yellowsn0w for use of your phone this is not for you as it will make yellowsn0w non-functional. Also you must be a registered developer to be able to run the 3.0 software successfully.
But if you’re daring you can download the Windows only software here.