To complement Colin’s recent gripes about the problems he’s been having with his Powerbook, I figured I should mention another issue that’s popped up on the Apple radar recently: The mysterious and baffling ease with which customers are scratching the faces of their iPod Nanos.

Now, I’m not going to rehash the problem. You can read the original article posted on cNet here. Or you can read through the informative (and sometimes emotional) thread at the Apple forums here.

No, instead I’d like to guess what the cause might be. Some people say neglect, others say poor design and construction (which as you’ll see might be true, but not necessarily intentional). I tend to believe it’s a little more basic, and at the same time a little less obvious. It might be the plastic.

Plastics are ubiquitous. They’re everywhere. To paraphrase Morpheus from The Matrix: “It is all around us. Even now, in this very room. You can see it when you look out your window or when you turn on your television. You can feel it when you go to work… when you go to church… when you pay your taxes.”

But not all plastics are created equal. What most people call ‘plastic’ is a family of synthetic and semisynthetic polymers that include bakelite, PVC, urethane, styrene, acrylic and nylon. What most people call ‘plexiglass’ actually isn’t.

Plexiglass is a trade name for polymethyl methacrylate. It also goes by the trade names ‘Lexan’, and ‘Lucite’. It’s used to make aquariums, lenses for tail lights, and helicopter canopies. It’s malleable, easy to produce, and durable, if not incredibly scratch-resistant.

The other commonly used clear plastic is polycarbonate. Made tougher, it’s used for CDs, DVDs, and eyeglass lenses. It resists scratches and breakage really well, but is of course much more expensive.

Now, I haven’t been able to find the data sheets on materials used in the construction of the Nano, or any other iPod for that matter. But if earlier (or more expensive) iPods use polycarbonate and the nano uses polymethyl methacrylate, possibly to save on production costs, well… that could go a long way to explaining the ease with which the Nano’s screen can be scratched.

At any rate, I understand my theory is not necessarily a new one. I merely posit my own opinion. I could be totally off-base, along with everyone else who’s thought of this. The one thing I do know is that if Apple skimped on materials to save money, the grumbling will only get louder. And if they don’t address the problem soon, they might find themselves in real trouble with all their loyal fans.