Apple is reportedly experimenting with wristwatches made of curved glass, a project that could add another profitable product to the company's iOS arsenal.

Writing for the New York Times, Nick Bilton cited people familiar with Apple's tests and reported other signs of Apple's interest in wearable devices.

Apple is not the only company exploring this area, as can be seen by the departure of Richard DeVaul, one of its high-profile wearable computing hires from 2010 who left Apple to join Google in 2011. Google is expected to soon release a developer prototype of its Project Glass eyeglasses and the wearable era will face its first mass-market reality check.

Understandable as it may be that the tech industry would like to see wearable devices follow the same explosive growth trajectory as the mobile market experienced over the last six years, Apple, Google and other companies in this space have yet to demonstrate there's any mass-market value to buckling, strapping, mounting or otherwise attaching small, Internet-aware computers to one's body.

There is certainly niche-market value: The Nike + iPod sensor, the Nike Fuelband and other activity-tracking gadgets like the Jawbone UP wristband are loved by some. But these specialized gizmos will never have the broad impact of the iPhone.

The reason is simple: Having an Internet-connected computer with audio and video capabilities in your pocket turns out to be transformative. Having a strap to attach a less-capable Internet-connected computer to one's wrist is something less than that.

[ Want another opinion? Read Why Apple iOS-Driven Smartwatch Makes Sense. ]

The problem with wearable computing is that "wearable" barely matters as a modifier of "computing." Squeezing a processor into an iPod Nano form factor mostly means a less-capable computing device, and adding a wristband doesn't change that.

It may not always be so, once processor power consumption drops and energy generation through skin contact, radiant light, nano-chemistry and motion rises to the point that devices regenerate power at the rate they use it. But by then "wearable" will be far less interesting than "implanted" as far as computing goes.

"Wearable" matters more at the moment for Google's Project Glass, because the form of the device is critical to its function. "Wearable" for a timepiece is largely a matter of convenience and preference. Millions of people already have a Pocket iWatch, otherwise known as an iPhone. The wrist-mountable equivalent of the (as-yet) nonexistent iPhone Nano won't really being anything new to the table.

Watches and glasses are different from computers in that they're sold as fashion accessories and status symbols. The form matters more than the commodity function, telling time. Why else would anyone pay hundreds, thousands or tens of thousands of dollars for a luxury watch?

Former Apple designer Bruce Tognazzini has penned an essay on the merits of an Apple iWatch. But I find it unconvincing. The two "killer applications" he cites, passcode management and iDevice location, are nothing of the sort. Rather than relying on the iWatch to eliminate iPhone passcode entry, the iPhone would be better off with biometric access support. And finding one's iPhone can already be done well enough through iCloud.