The thrill of taking a Motorola Droid or iPhone 3GS out of the box comes with a measure of anxiety. This phone, so perfect and so pure—in your clumsy, sweaty hands. How will you keep it safe? What if your precious gets scratched, or scuffed, or broken?

Don’t worry—there’s a product just for you. Actually, if you’re shopping at the Apple Store, there are 143 products: hard plastic sliders, striped cotton iPod socks, textured skins, scratch-proof films, titanium jackets, branded silicone covers, precision-stitched folios, and phone wallets made of fine Italian leather. A survey conducted in July found that 40 percent of U.S. wireless customers have carrying cases for their phones, as a bulwark against bumps, scratches, and dust. Some models claim more extravagant benefits: resilience to extreme temperatures, for example, or “antimicrobial protection” (lest your phone sprout mold or decompose). In September, Pong unveiled a silicone iPhone protector that wards off nicks as it “redirects radiation away from your head.”

Most cases run $30 or $40—about one-fifth the cost of a top-notch smartphone—but fancier versions are available. According to Michael Morgan of ABI Research, the global market for “carrying accessories”—a category that includes belt-clip holsters, leather sleeves, and silicone sheaths, among other products—has grown to $2.1 billion per year. But it’s not clear how much protection you get for the money. Hooman Morvarid, proprietor of the phone repair company CellularDR.com, says there’s not much chance that dust will plug up your charge port or headphone jack. (If it does, just spritz it with an air can.) A well-made case may help prevent a glass touch screen from breaking, but Morvarid thinks that’s not the main thing owners should be worrying about. The most common problem for any cell phone is water damage—from drops in the toilet, spilled drinks, ear sweat in the speaker holes, etc. When it comes to aqueous cell phone catastrophes, a standard case offers no protection at all.

So, what’s the point of these protective covers? If you’ve laid out for one of those smartphones with the black chrome bezel and the glossy face, the form of your device is likely as important as its function. Rubber sheaths and plastic films promise to sustain a gadget’s gleaming curves right out of the box. Apple consumers have shown a particular obsession with aesthetics: In 2005, fanboy mobs decried the first-generation iPod nano for its tendency to get scratched and scuffed. After Wall Street Journal tech guru Walt Mossberg joined in the complaining—”my recommendation now is that nano owners must buy and use a case for the device. … I don’t consider it optional”—a class-action lawsuit was filed. Apple agreed to a $22.5 million settlement this past January, with payouts to all those who “experienced scratching … that impaired your use or enjoyment of your iPod nano.”

If scratches can impair one’s enjoyment of a shiny gizmo, then what about a case made of bulky rubber? Manufacturers say the cases are “sleek” and “form-fitting.” No, they’re thick and ugly. This raises an obvious question: Even if carrying accessories do preserve a gadget’s tender frame, so what? No one can admire your iPhone’s unblemished skin when it’s sheathed in the tread of a car tire. Since covered phones can’t be admired by anyone but their owners, there must be some unspoken pleasure in the idea that you—and you alone—can lift that burqa of molded silicone.

Our fetish for virgin phones has spun off into a series of disturbing YouTube clips—not so much gadget porn as gadget S&M. In these homemade vids, anonymous men subject their delicate flowers to the most brutal degradation. A teenager jabs his touch screen with a 2-inch blade. A shadowy Eastern European tries to smash his phone with a Phillips-head screwdriver. These vignettes always end the same way: The key scrapes across the glass … and the gadget emerges unscathed. High-end phones—or at least their screens—appear to be stupendously resilient.

Nevertheless, screen protectors and phone cases have been around for as long as we’ve been making mobile calls. In the early days, we kept our cellulars in leather cases with wrist straps: They were status symbols, to be dangled like jewelry or tucked inside a briefcase. By the mid-1990s, carrying cases were earning a 45 percent profit margin for manufacturers, compared with 12 percent or 15 percent for mobile hardware. Clinton-era tech columnists were wary of the new industry’s cash cow: “Some retailers push expensive carrying cases,” warned the San Francisco Chronicle in 1995. “Don’t bother. It’s just as easy to stick them in your briefcase or purse.” In 1998, the Cleveland Plain Dealer advised stuffing your ears to “the siren call of … leatherette carrying cases (an old eyeglass case works just fine for most phones).”

The craze for cases seems to have fallen off somewhat in the early 2000s (although it’s hard to know for sure). Cell phones got cheaper and more widespread, and their customer base grew beyond a narrow class of leather-toting executives. More importantly, the phones themselves began to change. The success of the Motorola RAZR—which debuted in time for Christmas 2004—marked the heyday of the clamshell flip phone. Now each handset comprised two parts, an inside and an outside. With the device snapped shut, its screen and buttons were naturally protected, and a little wear-and-tear on the husk was no big deal.

Then came the iPhone. All of a sudden, the candy bar was back. Since then, the market for high-end, touch-screen phones has seen double-digit growth while the rest of the industry has stagnated. Generally speaking, the new products are more expensive, more useful, and more exposed than any phones that have come before. They also demand a new generation of accessories. If the iPhone redefined the mobile platform, the silicone-rubber iPhone shield redefined the carrying case.

I should pause here, in this history of cell phone armor, to make the following confession: For more than a year, I’ve carried an unadorned 16GB iPhone 3G in the back pocket of my jeans—whenever I sit down, it’s between my ass and my chair. It never occurred to me to wrap the thing in rubber or titanium; I never drop my phone, nor do I mind the scuffs and hairlines that show up, from time to time, on its white plastic base. But now, in the midst of researching and writing this article, a full-blown crack has inexplicably appeared on the face of my touch screen. It’s 1.5 inches long and runs diagonally from the edge of the speaker slot to the bottom of the volume controls on the left. I swear it happened on its own—an act of God or karmic payback—while the phone was nestled safely in my pocket over the weekend.

As of Sunday afternoon at about 2:15 p.m., I’d planned to conclude this column by saying that cell phone cases aren’t worth the money. Now I’m not so sure: This crack is pretty annoying.

It seems that there are no universal laws of cell phone breakage. Some people bounce their phones off concrete sidewalks with no ill effects. Others manage to shatter an iPhone with one gentle drop. Buying a protective sheath seems a bit like getting a not-so-comprehensive insurance plan. If it makes you feel better, go ahead, but your phone could very well break in your pocket for no apparent reason.

Rather than recommend that we all go out and buy the OtterBox Defender, I’ve got a better plan: Let’s buy gadgets that don’t need any armor. I want my next phone to be one that’s built to survive 15 months in my back pocket—and a few dunks in the john. They say you can’t build a whole airplane out of the black box. But that’s not true for cell phones.

“Rugged” phones have been around for at least a decade. (Remember those rubberized, yellow-and-gray Nextel phones for construction workers?) Now there’s a thriving niche market for gadgets that meet the super-tough standards of “military specification 810F.” These may not have all the bells and whistles of the latest smartphones, but they are compact, powerful devices that won’t crack open when they fall out of your purse.

I might choose the low-end Samsung Convoy (available for $49.99) or the full-keyboard G’zOne Brigade. You don’t need to get stuck with an ungainly brick, either. The waterproof, GPS-enabled Sonim Land Rover S1 weighs less than the Motorola Droid. And did I mention that it’s impervious to salt, fog, humidity, and petroleum oil?