Apple gifted all iPhone 3GS owners with an exploit so that we can jailbreak and unlock our iPhone 3GS to our heart’s content. But here is the catch! The exploits WILL be closed in the next firmware upgrade which is due any minute now.
So here is the thing : PLEASE DO NOT UPGRADE TO iPHONE 3.1 before performing the following procedure (if you want to unlock/jailbreak that is!). Dev Team is waiting for the next release (iPhone 3.1) so that the Apple will not close the jailbreak exploit. Jailbreak for iPhone 3G S will be released soon.
Watch the Windows version for a first hand experience!
It might sound confusing, I am sure. All you are doing here is ENSURING that you can jailbreak or unlock your iPhone 3GS in the future. This is just a preparatory step for all you unlock hopefuls! Why take a chance when you are warned way ahead?