The iPhone Dev Team released its iPhone 3G unlocking utility, yellowsn0w, on the first of the year although it’s still a beta.
If you’d like to crack your iPhone with the beta remember version 0.9.4 beta works only with iPhone baseband 02.28.00, that’s the version installed by iPhone 2.2 Software Update, Apple’s most recent firmware update. So before you start use yellowsn0w, make sure to use iTunes to upgrade your iPhone to 2.2.
If you’ve used QuickPwn to perform a basic jailbreak before and you use Installer to load apps then you should be able to use this beta with no problems – otherwise I’d advise waiting until the non beta version is ready as I’m sure there will be better support available then when they are not concentrating on the new version although there is some basic help available now
Allegedly you won’t notice anything about it other than that your third-party SIM now works.
I’ve not tried it yet as I’m not going anywhere that needs a different SIM – always my big gripe when I am in Australia with the iPhone. I’m likely to wait to the 1.0 release.