Description

 This is software which will allow a full jailbreak for any iPhone, including the 3G S running new 3.1.3 firmware.

Instructions :

Simply plug your device into your pc, run the spirit application. The software will automatically detect which device you have plugged in. 
One click on jailbreak and within 2 minutes, your device will be fully jailbroken.

NOTE:
Please backup with iTunes prior to jailbreak incase of any failure.

Please comment on how this worked for you.

Enjoy.