Apple iPhone 3GS - Jailbroken on iOS 4

The Apple iPhone 3GS has been jailbroken by msft.guy who fixed the iPhone unlock for 3.1.3 on baseband 5.11.07. and ported it to iOS 4. The jailbreak is done using PwnAge tool, while preserving the baseband of your iPhone. You can unlock your device using ultraSn0w or blackSn0w. The video below shows the working jailbreak

The Dev Team has promised a jailbreak and an unlock for iOS4 sometime this month, so its best to wait for the official PwnAge 4.0 tool release before attempting this.