I have tried since yesterday when my iPads arrived to register with AT&T using the sign up screen provided. I always get the same message asking me to validate my address. I have contacted AT&T and Apple Tech and was finally told by the Apple Tech to take it to the nearest AT&T store and maybe they could get it to complete. I took the 30 mile trip to the nearest store and the guy there went through the signup process only to get the same message. He called me a while ago and said he spoke to Apple and that I should call them back again. Thank goodness I have wi-fi in my home or I would have been totally unable to use my iPad. Anyone else with this problem?