If you are stuck with an iPhone 3GS having newer bootrom (iBoot v 359.3.2) and want it to be jailbreaked here is some great news for you - iH8sn0w Sn0wBreeze utility will soon be upgraded to support tethered jailbreak (meaning you will have to re-jailbreak if your iPhone reboots) of iPhone 3GS having iBoot v 359.3.2. The only catch is that you must have your iOS 3.1.2 ECID saved as you will need to downgrade for this to work.