wrote

So if I go this route and try using the internet through the Alltell data
network, it's my risk and I know that. XM isn't really a consideration
for
me as I want this service for just one long cross-country each year, when
my wife and I fly from Wisconsin to Texas to see my parents. It'd hardly
be worth buying a new GPS and signing up for XM for one trip per year. If
we sign up for Altell's plan, we'll be using that for our home internet
service as well as for the one annual flying trip. I hope that explains
my
motivations better.

Go for it, if you feel so led! ;-)

I think you will still find that you will have to go down to 2500 feet, or
so, to get any service. If that fits OK, good, it would be handy, I guess.
--
Jim in NC