iPhone 3GS 3.1.2 - Jailbroken!
Well, it's been out for a week now and there isn't yet a thread for it. So, for those who don't know yet, the latest firmware for the iPhone 3.1.2 has been jailbroken. Geohot has released the tool you need called blackra1n.
It is the easiest jailbreak ever apparently. I say apparently, because it's the first one I've ever done! :p Shut down iTunes, connect up your iPhone, run blackra1n and hit the big button that says "Make it ra1n" and about 30 seconds later your iPhone is jailbroken!
[ame="http://www.youtube.com/watch?v=kk6x4yGbflw"]YouTube - Easy Way How To Jailbreak NEW 3.1.2 Firmware For All Devices Windows/Mac Blackra1n[/ame]
I've successfully jailbroken mine and loving the results! A few things to note:
Listen to the warnings! If you require an unlock (basically if you are not on O2 in the UK, do not update to 3.1.2. This will change your baseband and you will not be able to use your phone with your non O2 sim! blackra1n also doesn't activate.
Once you have jailbroken, when you run blackra1n, do not install Cydia, Rock and Icy together! I noticed issues with Winterboard and other programs when installing all 3 together. Install each separately. I rebooted after each install.
blackra1n does not add the afc2 service with the jailbreak causing issues with some tools. There is a handy guide here telling you how you can add this to the phone.
Once all that is done, you can finally unleash the true beast of a phone that Apple has so wrongly kept tamed! :)