Update (06072009): Purplera1n for Mac OS X released, works the exact same way, scroll down for instructions on use!

So far the iPhone Dev Team have been reluctant to release their jailbreak and unlock tool for the iPhone 3GS. Though the Dev Team says this is possible, they feel that iPhone OS firmware 3.1 which may soon be released will cause a rapid repeat of their cat and mouse game with Apple. So where is this non-Dev Team jailbreak method coming from? George or GeoHot says the following…

Normally I don’t make tools for the general public, and rather wait for the dev team to do it. But guys, whats up with waiting until 3.1? That isn’t how the game is played. We release, Apple fixes, we find new holes. It isn’t worth waiting because you might have the “last” hole in the iPhone. What last hole…this isn’t golf. I’ll find a new one next week.

Though George did say the above, its important to note that if you have the iPhone 3GS and want to make sure that your iPhone 3GS is unlockable under future releases of new firmware, you should NOT yet update to 3.1 even if you have access to it. The reason for this is that the unlocking tool ultrasn0w which has been tested to work for the iPhone 3GS also relies on the iPhone 3GS’ baseband, updating to 3.1 without the assistance of a tool will affect it, as mentioned briefly by the iPhone Dev Team:

“injection vector will be lost if you update to 3.1 using the official Apple IPSW, which updates the baseband.”

iPhone 3GS users, we must also warn you because the below tool for jailbreak by George / GeoHot isn’t the official tool from the Dev Team, it would be difficult for us or many to provide you with any support should anything happen to your iPhone 3GS during the jailbreak. But GeoHot has mentioned that you can contact him via a support email which he has provided on his blog.

So here’s how this iPhone 3GS jailbreak tool known as purplera1n (yes, purplerain) by GeoHot works:

Tips before you start:

• Backup!
• You will need to be running Windows XP / Vista / Mac OS X not Windows 7.
• You will need to be using the latest version of iTunes.
• If you don’t see Cydia installed after jailbreaking, just reboot your iPhone 3GS.

Steps / Instructions to Jailbreak:

1. Download purplera1n.exe (Windows) or purplera1n.zip (Mac OS X).
2. Connect your iPhone normally.
3. Click “make it ra1n” then wait.
4. When your iPhone boots up, run Freeze, the purplera1n installer app.
5. Then follow what the app says!

Once you have jailbroken successfully, all you need to do to unlock is use ultrasn0w as if you had the iPhone 3G.