I have AT&T as my provider but just bought a Unlocked RIZR Z3 on Ebay. I am told that if I want to use the internet at all with this phone I need to get the setting changed somehow to AT&T. I don't use the internet at all through the phone but maybe when using Motorola Phone Tools it needs to access the INTERNET?? I don't know???

HELP - How do I change the setting of this new unlocked phone to AT&T and do I really need to do this to just download my ringtones and pictures that I made on Motorola Phone Tools on my PC?

Will I be able to send and receive text messages and photos as well?