All iPhone / iPod touch owners, DO NOT UPDATE your device to Apple's latest software release, version 3.1.3! As of the moment, there's still no 100%-working jailbreak for this version and possibly, there won't be any. So if you care about your jailbreak and unlock, or if you plan to jailbreak and unlock your device in the future, keep it to version 3.1.2. 

According to jailbreak experts, there's not much improvement on this new version, except for the promise of a much faster speed which is hardly noticeable.

If your device is currently running on a much older version, click here and download the 3.1.2 IPSW and restore, at least you're 1-step behind the latest version. If you want to know how to jailbreak your device, watch out for my post, I'm in the process of completing the guide for that, but if you can't wait a little longer, Google might help you. 

To guide you on restoring your device to 3.1.2, please read this instruction.