Pandora is internet radio; you pick an artist or song that you like and it builds a station of music with similar qualities. If it plays a song you don’t like, a click on the thumbs-down icon helps Pandora refine what it plays for you.

I’ve never used an application that loaded any easier or was more intuitive to start up. Over the course of a 45-minute drive in which I was the passenger, I loaded it, got familiar with the controls and set up about 15 stations — all of which play music that I could listen to all day. When I got to my laptop, I loaded the application in less than a minute, then typed in my password, and got to precisely where I’d left off on the Blackberry.

With a $6 cable from Radio Shack, you can plug the Blackberry (or iPhone) into the utility port of a car radio or a set of powered speakers.

Which means that with no learning curve, and for the cost of my cell phone data plan — which I was already paying — I can have the best of all musical worlds (mental note: start a new Pandora station around Candide or Leonard Bernstein).

It’s better than my iPod, because I don’t have to select each song and be my own DJ.

It’s way better than Sirius/XM because the channels I create are better focused than anything satellite radio offers; and I don’t have to pay the $6.99-$12.99/month subscription fee.

I don’t think Pandora is going to hurt the sale of MP3 players; most of them do more now than simply play music files.

But Pandora is everything that Sirius/XM could hope to be — yet easier, better and cheaper. It is the ultimate disruptive technology; it delivers radio at no cost, using technology that lots of people already possess, and it strikes a magical balance between doing all the work and giving the user control.

Last I heard, Sirius/XM was losing more than 100,000 customers a month. I can’t imagine that pace has continued. But I’m guessing the downward trend has. And with its dependence on expensive space-based satellites and human-programmed channels, satellite radio is a precarious business model that has yet to make money.

In Greek mythology, Pandora carried a magical box that contained all things harmful to humans — disease, fear, unhappiness, etc. Zeus instructed her not to open it, but when her curiosity got the best of her, she spilled its contents into the world and upon mankind.

To most of us, this Pandora is a welcome innovation. But to Sirius/XM — and broadcast radio over time — Pandora and the others that will inevitably follow it must look like the thunder from Olympus itself.

And if you’re the folks at Sirius/XM, it’s the kind of number that puts you into a full-blown panic attack. When you lose 400,00 customers in 3 months, you start asking questions like, “Are we doing the right thing here?” and “WTF?”

My personal experience is that I had been a subscriber for 2 years when I got a note from Sirius/XM in February warning me that I would no longer be able to access programming for free on my computer unless I paid for the full year in advance right away.

It annoyed me, and I immediately assumed it was a cash-grab. But I bought the 12-month subscription because I thought it was important to me. Two weeks later I lost my job, and a week after that, in an effort to cut all unnecessary costs — and because I was irritated at being leveraged in the first palce, I called to cancel my subscription.

Their response? The nice lady with a Punjabi accent asked if they could keep me as a customer if they reduced the annual subscription rate by 50%. Now I was really mad, realizing that all along I’d been paying twice what they were willing to take. I told her no.

A month later, I got a direct-mail piece asking me to come back at 4.99 a month for six months — 38% of the original price. I suppose this was supposed to entice me. But it made me feel even more stupid for having paid $12.99 in the first place.

There’s one other thing: All along, Sirius/XM has advertised that it’s commercial-free radio, which should be worth paying for. But it’s not true. If you listen to any syndicated programming that’s re-broadcast via satellite, you’ll get the same amount of commercial time as you would on commercial radio.

And if you listen to their original programming — some of which is really pretty good — you still get advertising. And it’s the most irritating kind: low-budget stuff for whole-body cleanses and businesses that you can run from home without any skills or experience required.

I originally bought my XM subscription because I didn’t want to be my own DJ; I’d rather have someone else do it for me. But these are hard times, you know. Worst times since the Great Depression. So now, when I get in my car, I plug in my i-pod or put in an old CD. I still don’t want to be my own DJ. But I’m guessing that 399,999 other people agree with me that it’s not all that bad a job.