Now you can unlock Apple iPhone 3.0 firmware by using RedSnow for 2G iphone only.

Redsn0w is an easy to use jailbreaking and unlocking tool for the iPhone 2G , the iPhone 3G (but not the 3GS) and also the iPod touch (first and second generation). Currently it is available for Windows and Mac OS X (there are some issues using redsn0w with OS X PPC, please use an Intel Mac until we have this problem resolved).

Redsnow provides similar functionality to QuickPwn.

To use redsn0w simply upgrade the device to  firmware version 3.0 and run redsn0w to activate and jailbreak the device.

If you are using an original iPhone 2G, it will unlock it .