I have an Iphone 3GS with the latest firmware and I want to be able to take it to another provider.  My current provider wants to charge me $100 to shift carriers. 

I am in Australia if that makes any difference.

Pretty please?

I'm not very familiar with the unlocking scene, but last I heard, the latest iPhone OS release borked up jailbreaking. I'm sure it won't be too long before the hackers figure out a new plan of attack, though.

Edit: A little Google goes a long way.

This is the place to go for jailbreaking:

http://blog.iphone-dev.org/

Note that PwnageTool is Mac OS X only and can unlock a 3.1.2 phone. If you're a Windows or Linux user, you'll want to wait for redsn0w to update. There's another tool called blackra1n, but it sounds like it's a little dodgy.

Have fun, and try not to brick your phone.

honestly there really is no secure or safe way. when bringing something out of its programming there is always potental to "brick" it i am a mac user and i really wouldn't suggest it. Macs are machines that require you to run updates irregularly so its hard to tell. and then on top of that if you dont update it it WILL start to act funny. if by chance you do "update" it no doubt it will crash. and there is no recovering. it almost more trouble then its worth. Also since it's an iphone as soon as you connect it to your computer it will try to update adn thats also dangerous. Honestly dude just go for at&t.

The best tools are redsn0w and ultrasn0w. Redsn0w is just for jail breaking your phone so you can run more apps on it. Ultrasn0w is for hacking the modem to use on other carriers (T-Mobile usually in the US)

Here are the links.
http://blog.iphone-dev.org/post/126908912/redsn0w-in-june

I think if you have the latest firmware, and have the latest OS, you might be SOL at the moment. Not sure. I have not read these in a while, but I thought part of iPhone OS 3.1 was geared to stop this sort of thing.

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