blackra1n is currently available only for Windows users.
Geohot has provided the following details about his new jailbreaking tool:
So, what is blackra1n? blackra1n is a 30 second ALL device 3.1.2 jailbreak. Even the ipt3, but the ipt3 is tethered. In order to boot it, just rerun blackra1n.
Warning 3g and 3gs unlockers, do not upgrade to 3.1.2 using iTunes if you want to keep your unlock. Baseband cannot be downgraded. Check out the dev team's offerings. Also blackra1n doesn't hacktivate.
So if you want to unlock your iPhone then you will have to wait for iPhone Dev Team to release a new version of their PwnageTool, which allows you to upgrade to jailbroken iPhone OS 3.1.2 and also preserve the baseband. Dev Team has confirmed that they are working on PwnageTool for iPhone OS 3.1.2.
If you want to only jailbreak your iPhone and don’t care about unlocking it, then you can try blackra1n by downloading it from this link.
Please remember hacking your iPhone could void its warranty. So please proceed with caution. It is always a good idea to take a backup of your iPhone before you hack it, refer to this post for more details.
If the solutions works for you, don’t forget to drop over at the blackra1n’s website to give Geohot a donation for all his hard work.
As always, if you give it a shot let us know how it goes.
Thanks tigger and Pooh for the tip!
[via Geohot’s blog]