I have an AT&T plan that is grandfathered from about 5 years ago. It's an amazing plan that I don't want to change from. The SIM is from the old AT&T Wireless, before they switched to Cingular and then back to AT&T again.
Is it possible to unlock the iPhone without jailbreaking it as well? Also if I only unlock it, will it cause any problems with the 1.1.3 firmware or will it cause any problems with any of the features/programs?