The other day, while driving home on Interstate 15, I was approaching a sport utility vehicle that had one of those newfangled onboard DVD entertainment centers. You know, the ones you can't possibly miss when you're behind them.

As I prepared to pass, I noticed this time that it wasn't SpongeBob SquarePants beaming from the screen, as is often the case when I encounter one of these mobile marvels of modern technology. Instead, the back-seat passengers were watching a baseball movie.

Being a longtime baseball fan myself, I craned my neck and squinted my eyes to see if I could determine exactly which film they were watching. For a second, I thought it was a scene from my all-time baseball favorite: "The Natural." (Yes, I'm sort of a romantic about the sport. I still remember the day when stars actually played because they loved the game and signed autographs for young admirers without grumbling.)

But I digress.

In that brief moment, I couldn't be sure about the movie. And it wasn't as if I had the luxury of lingering for a few more seconds to confirm my suspicions.

Refocusing my attention on the road, I changed lanes, passed and went on my way.

These back-seat systems aren't exactly ubiquitous yet. Sometimes you see a whole slew of them; other times you come across only one or two.

But there is no denying their growing popularity. The Minnesota-based Telematics Research Group predicts the devices will be in 22 million vehicles worldwide by the beginning of the next decade.

It's not hard to see why. Moms and dads weary of having to calm restless, squabbling siblings in the back seat are probably dreaming of driving bliss when they plunk down several hundred dollars to buy an onboard DVD screen.

Of course, you've heard the main argument against the devices -- that they are invading one of the last distraction-free refuges of modern society where families can carry on a conversation without interruption.

That argument aside, what about the distraction the video screens are for other drivers? When there's a rectangle of bright, colorful light floating in the back window of the car in front of you against the backdrop of a darkening twilight sky, chances are you're going to be tempted to look at it.

To be sure, technological advances are great and a lot of new gadgets are making driving safer. I'm not sure this is one of them.