Well, right now, I have an iPhone 2G with a 20 dollar data plan that also includes 200 texts. It's part of a family plan, and I'm probably going to go Samsung Captivate or iPhone 4 in a few days. My questions include 1. Can I just use the 20 dollar data plan for the iPhone with that phone, like, without them knowing? Any serious consequences involved with it? 2. Similar to the first question, can I just use the non-smartphone data plan, which is 15 bucks a month, and use that with the Captivate? Would they know which phone is using it? 2. Once I switch to limited data, like 200 MB or 2 GB, can I switch back to unlimited? I don't pay my own bills, parents do, but don't want to put on an extra 10 or 15 dollars a month right now, just for data, when I could just continue using whatever I'm using.