Then what is the deal with tethering? If the cost is as much as an air card what is the advantage. Similarly, I see emails sent from phones all the time. Do those cost $70 a month just to be able to do that as opposed to $40 or so per month?

If I want to get on line when we travel (not sure about that, it's nice to not have phones ring or to feel compelled to get on the computer) I would only do it to get on the POG forum and answer emails. Wouldn't a phone work?