Go to the store with the phone and purchase a new SIM card (approx $20) and activate your new device on the Family Talk plan. You will only pay an initial $18 activation fee on your next billing statement. You can either go to an authorized agent or a retail location.
I have one TDMA phone with Cingular (actually ATT Wireless). It's used by my wife.
I want to add an unlocked GSM Treo 650 as a second Cingular cell phone on a "family plan". I *do not* have a Cingular SIM card. How do I get one for my unlocked Treo 650?
Can I go to a Cingular store with my Treo where they will give me a SIM card once I add the phone to our existing account? Or do I need to do it by phone? (Or do I have to sacrifice my first-born child?)