Quickpwn is a popular tool to jailbreak the iPhone and it has been using for earlier firmware version but with the latest release of firmware of iPhone 3GS OS 3.0, it seems very difficult to jailbreak the iPhone.

You can also use Purplera1n to jailbreak your iPhone 3GS easily.

For this purpose iPhone Development team has released the new version of Redsnow o.8 and now by using this version one can jailbreak the latest firmware easily. To unlock the iPhone it is necessary that you first jailbreak your iPhone.

Here is a step-by-step tutorial to jailbreak iPhone 3GS using RedSn0w for Windows and Mac users. As told that to unlock your iPhone you need that your iPhone is jailbreaked. After jailbreaking follow this guide to Unlock Your iPhone 3GS OS 3.0 With RedSn0w.

After unlocking iPhone 3GS with Redsnow, reset your network setting from Settings->General->Reset->Reset Network settings once. The whole process is similar toiPhone 2G and 3G jailbreaking.

What is Needed for Jailbreaking?:

1. Download Redsnow for Windows | Mac | Linux
2. Download iTunes 8.2
3. iPhone Firmware 3.0 for iPhone 3GS

After downloading the required softwares, follow the simple steps below and you will be able to jailbreak your phone successfully.

—First of all: Make a folder on your PC and place all downloaded files in it and run the Redsnow from this folder and select the 3.0 firmware ipsw.

—Click on Open button and continue the process.

—In next Window check the Install Cydia option to Jailbreak your iPhone.

—Turn off your iPhone but make sure that it is still plugged in with cable and put iPhone in DFU mode.

—To go into DFU mode: Hold the Power button for 3 seconds; hold the Home and Power buttons for 10 seconds, then release the Power button and continuing holding the Home button until your iPhone is in DFU mode.

—If you have successfully put your phone into DFU, you will be allowed to continue. Otherwise you will have to repeat the whole process.

Hurrah, after 8-10 minutes you will have your iPhone jailbreaked.