I have an iPad (1) 3G. I've never used (or activated) 3G but will likely do so in the next week or so, and I'm confused on some stuff. 1) Do I have to use AT&T or am I apple to use Verizon? 2) If I can use Verizon, do I need a new Micro-Sim card? 3) Is the account set up thru the iPad? Do I need to go to a store or website? 4) I'm mainly looking at this for google maps app. (I'm doing a road trip). How much data does maps need? Would the 250mb plan work ok? Thanks for any help.