once the iphone is activated you can take your sim card out and use even a deactivated sim, you will still have your regular functions. the iphone is only completly crippled if you did not activate it yet.
also it says any ATT sim card, they have not unlocked it to any provider because its way more difficult that people had originally though. i dont have the link but they said they need a certian key to tell the iphone to accept other sim cards, this key must match a certian set of numbers on another providers sim.
also stated that brute forcing the key will take too long, someone will need to "leak" the key or another way needs to be found (rewrite the firmware for the radio?)
