PwnageTool has just been released and with this release there’s finally a tool to jailbreak iPhone 3GS on iOS 4. Although PwnageTool 4.0 works only on Mac and you need to have iPhone 3GS on old bootrom. Furthermore you should have jailbroken your iPhone 3GS already in order to use PwnageTool 4.0 jailbreak tool. If you fulfill these requirements, follow the step by step guide posted below:
Note: Users who used spirit jailbreak for iPhone 3GS can’t jailbreak with PwnageTool.
Before you Begin:
- Remember to backup your data and contacts.
- Download original iOS 4 for iPhone 3GS or 3G (Direct download links)
- Download PwnageTool 4.0 for Mac [Torrent | Mirror 1, 2, 3, 4]
How to Jailbreak iPhone 3GS & 3G
Step 1: Connect your iPhone with Mac
Step 2: Run PwnageTool 4.0, it will detect your device
Step 3: Browse for downloaded IPSW for your device
A dialog box will appear asking “Do you have an iPhone contract that would activate normally through iTunes?” Clicking yes will update your baseband.
Step 4: Click “No” if you rely on baseband unlock, click “Yes” if you are on official carrier and don’t need to unlock your device.
PwnageTool will process the jailbreak now. Once the process completes you will see “ihaz Success!” message on screen as it appears in screenshot:
Step 5: Your custom IPSW is now ready. Load custom IPSW in iPhone, (see how to).
Note: We have already published a more detailed guide to jailbreak iOS 4 with PwnageTool. If you face any problems in understanding this guide, you may download the required things from here and then head on to our guide for how to jailbreak iPhone 3G, 3GS with PwnageTool.
After jailbreaking, you can unlock iPhone using ultrasn0w 0.93. Windows users should wait for sn0wbreeze 1.6 release to jailbreak iPhone 3GS iOS4 on Windows.
gilberto 
