The iPhone Dev Team is promising a software unlock for the iPhone 3G by the end of 2008. Back in October the iPhone Dev Team signaled they were getting close to their goal, and Tuesday they announced that a software download would be available on New Year's Eve. The iPhone 3G has presented problems for those looking for a simple way to use their phone on the mobile network of their choice after Apple fixed a loophole that left the original iPhone wide open to unlockers.
There are ways to manipulate the SIM card that comes with the iPhone 3G to use it on the network of your choice, but that's not something the average person should try at home. If you want to unlock your iPhone, you'll need to have jailbroken it first, and you'll have to have heeded the iPhone Dev Team's advice to avoid the iPhone 2.2 software update without applying a special patch first.
Source:→ C|Net News