I recently took a bit of a road trip for my summer vacation. All told, it was about 1,000 miles, starting in rural New Hampshire (is there any other kind?), down through New York into rural-ish Pennsylvania, and back again.

My rental Chevroocrap had two redeeming features: an admirable lack of spontaneous combustion, and an aux-in for a stereo that could best be described as "audible."

I never leave home without my iPod, but on this trip I decided to see how much I could use my phone as an entertainment source. I wasn't expecting any trouble. Otherwise I would have planned a more extensive test.

Using Pandora, a fairly data-intensive service, the stream was constantly interrupted, and I was warned repeatedly of imminent data-roaming mode (and the charges that come with it). It occurred to me, somewhere in the swath of boredom that is central Connecticut, that had I chosen to rely solely on cloud/streaming audio for this trip I'd have had to concede entire sections to - oh God - the radio. Just the thought is enough to terrify.

So that got me thinking. Everyone is all gaga (small "g") about these new cloud services. Al recently wrote about the MOG and Spotify services that let you play the music you want anytime, and in theory, anywhere. Pandora (and to a less popular extent, Slacker) offer unlimited music, largely free. Don't get me wrong, these are all cool . . . but can one really stop buying music?

What happens when you can't access the stream? I mused about ownership in the age of cloud a few weeks ago without thinking I'd have such a real-world test. I love owning music, and I'm happy to pay for it. But the trend is away from local storage or even ownership in general. If that's your bag, you're welcome to it. But there is no way you can be sure you'll always have access to the cloud, or even a data stream. When that happens, you're SOL. Maybe it's just for a few minutes, but maybe not. ?

I've included here the coverage maps from Sprint (my provider), the much maligned AT&T, and Verizon. If you trace a route from central NH to Philly, there appears to be coverage. Sprint is admittedly the worst here, Verizon apparently the best. But driving down the Hutchinson River Parkway into the most populous city in the country is not an area I'd have thought would be so lacking in wireless data signals.

This isn't to knock Sprint, with whom I've been very happy for over 10 years. There are plenty of places around the country where one provider (maybe even one's own) is better than another. (AT&T customers have told me that for them these places include "somewhere else.") Fortunately, Sprint is rather forgiving (at least with my plan) of data roaming. If yours isn't, and your phone/program doesn't disconnect when it goes off network, the charges could be extreme.

My point, rather, is a cautionary one: you can never assume you'll always have access to "your data" when "your data" isn't "your data." Proceed with caution; or, you know, just buy music.