So Nate True fro the iPhone Development Team has published the official iPhone Dev jailbreak for firmware 1.1.3. Needless to say, it’s a risky process, but what needs to be emphasized is that it is riskier than previous jailbreaks. The jailbreak developers themselves warn you in no uncertain terms:

As all upgrades are risky, this one is doubly so. You may have to restore your phone using iTunes and start again if it fails. Make sure to back up first!

Let’s continue

This jailbreak, like the 1.1.2 jailbreak, comes as an upgrade. This means you need to have a 1.1.1 or 1.1.2 jailbroken phone already, before you can begin.

It also need to be emphasized that this jailbreak comes as an upgrade. If your iPhone is not jailbroken, this will not work. Furthermore, before you decide to jailbreak your updated iPhone, hear this out: “It looks like Nate’s update causes Nikita to break (Nikita is the component on the iPhone/iTouch responsible for installing signed software, such as the iPod App Pack and likely SDK apps in the future).” This from an iPhone developer. Jailbreak at the cost of SDK and future third-party apps on your iPhone