While Canadians can get their iPhone fix directly from Rogers or Fido, there are still a lot of parts of the world where the iPhone isn’t quite as available. Further still, you may want to take your AT&T iPhone for use in Canada, for example, so that’s why you’d want to unlock the thing. This hasn’t been the easiest of tasks, but it has now happened!
With the arrival of firmware 2.2 for the iPhone 3G, the unlocking process got a little more complicated by the trusty iPhone Dev Team has created a solution that they call yellowsn0w. Don’t eat it. Just use it.
There are effectively six basic steps that you’ll need to do if you want to unlock an Apple iPhone 3G with firmware 2.2. Bear in mind that you are doing this under your own risk and you are 100% responsible for anything that may (or may not) happen as a result.
1. Update your iPhone 3G to 2.2 via iTunes
2. Jailbreak the iPhone using QuickPwn 2.2.
3. Open cydia, click on Manage, choose Sources, select Edit, click Add, enter this repository URL, and click to return to Cydia.
4. Search for yellowsn0w and install it. After installing, exit Cydia.
5. Reboot your iPhone with your chosen “foreign” SIM inside.
6. After 10 seconds, you should see a signal and your iPhone 3G is unlocked!
More information, including some useful links, can be found through the Read link below.