Cingular has begun to lax some restrictions on what customers can use what phones under the Cingular umbrella. Blue, formerly AT&T Wireless customers can now use orange phones, even locked ones.
The process is not automatic though, you must email firstname.lastname@example.org with the following information:
Your Account Number:
Your Mobile Number:
Your Phone’s IMEI:
Phone Make and Model:
The SIM Unlock Group will then give you instructions to unlock the phone. Of course, Blue customers are not able to obtain any discount, and must pay the full retail price for the phone.