Just few days back we saw how to jailbreak iPhone 3.1.3 via Sn0wbreeze. Here’s a way to Jailbreak your iPhone OS 3.1.3 via Redsn0w. This method can unlocks iPhone 2G, jailbreaks iPhone 3G, iPod Touch 1G and iPod Touch 2G. Follow these steps:

• Download and install iTunes 9.0.3
• Download redsn0w 0.9.4
• Download and install iPhone OS 3.1.3 on your iPhone or iPod Touch using iTunes, if you haven’t already
• Open Redsn0w and browse to OS 3.1.2 and click next.
• After redns0w has validated the firmware, it will show some options such as Install Cydia, Verbose boot etc. Make sure to check Install Cydia and Already pwned. Now hit next to patch the kernel.
• Start your iPhone or iPod Touch in recovery mode by pressing both the power and home button until the help message on redsn0w disappears (around 10 seconds). This is the DFU mode.
• Now press and hold the Power button.
• This will start the Jailbreaking process. Once done, it will restart your iPhone.

Here’s the video for better understanding:

This method is not available for iPhone 3GS yet, So do not try to jailbreak your iPhone 3GS using this method.