I am an Australian who will be moving to the USA in the future. I will be buying the iPhone 4S unlocked here in Australia. How will this work when I move to America? 1. Will the phone work in the US, and on any network. 2. What are my options for networks? I understand there is ATT, Sprint, Verzon, and T Mobile. I checked out their sites, and most pricing is for when you sign a plan for two years. I will be bringing my own phone. Since the carrier won't have to subsidise my phone, how do I go about finding a suitable competitive plan?