I have my iPhone 3G for two years now and my contract with AT&T expired. So I guess I am on a month to month basis contract??? Can AT&T give me an unlock code to unlock my phone and use it with another carrier?
I know AT&T is doing that with other phones but I am not sure if it follows the same practice with iPhones.
Authorized unlocking is done through iTunes with a request from the carrier. ATT/Apple will not unlock your AT&T locked iPhone under any circumstances. You can see a list of carriers and whether they support carrier unlock here: http://support.apple.com/kb/ht1937