When critics marvel at a piece of "great design," they usually mean an object or building that's fabulous-looking, the embodiment of some mind-blowing Big New Idea. Like Frank Gehry's Guggenheim Museum in Bilbao, Spain, a few years ago. Or like the original Palm Pilot in 1996.

When Apple introduced its G4 Cube computer last year, the enthusiastic chatter was mainly about the elegant look of the thing -- the novel shape, the small size, the transparent case.

In other words, appreciation purely on the level of what I call yuppie porn.

Now, my weakness for sleek, cool new products is as automatic as the next yuppie's. But what drove me to buy the Apple Cube instantly was a more utilitarian innovation that had nothing to do with fab style. Unlike every other computer, the thing was designed without a cooling fan. It's naturally air-cooled. Which means the Cube is an absolutely silent machine.

Who cares?

I care. As someone who spends hundreds of hours a year alone with computers, thinking and writing, that incessant PC fan sound has always been an annoyance, the pea disturbing my princess-y creative peace.

And so the G4 Cube is the first computer I completely love.

My point is that in design -- as everywhere else in life -- most breakthroughs are small, quiet, not so obvious. Even, at first glance, banal. They are the work of anonymous designers accomplishing real, functional improvements somewhere on the spectrum between incremental and profound. Designers for whom "new and improved" is not just a marketing cliché.

Dozens of new products are hustled at us every day, every year, unceasingly. So we've all learned to assume that something pitched as "new and improved" is not really either. That's what I thought about Gillette's Mach 3 razor when it first appeared three years ago. My cynicism was automatic. Its handle was decorated like a running shoe. It had a dopey "futuristic" name, and ads featuring jet pilots.

But then one day a level-headed friend spontaneously raved about the thing. "Three super-thin blades!" he said. "Spring-loaded pivots for each blade!" So I bought one.

And discovered that the Mach 3 evangelism was justified: it makes shaving easier and faster -- lots easier and faster, almost blithe. Maybe not a breakthrough on the order of the museum in Bilbao or the first Apple Macintosh. But, in its tiny way, actual and unmistakable design progress.

Like the Oral-B CrossAction toothbrush.

The Oral-B Cross CrossAction also came on the market a couple of years ago. It has several different kinds of bristles for several different kinds of cleaning action -- and a ridged, bulbous handle designed to fit human hands like a good tool.

Yes, I know: a toothbrush -- just about as banal as it gets.

But once again, a significant design improvement in an object we all use every day, hundreds of times a year. Like the Apple's Cube computer, small but important reminders that there is a difference between good design and nice packaging.

It's the sum total of such earnest little achievements that makes design a vital and not merely entertaining profession.

Not that design excellence necessarily carries the day in the real world.

As it turns out, the Gillette company makes both the Mach 3 and the Oral-B. Since the products were introduced, Gillette's stock has performed horribly. And last month, Apple Computer announced that because of poor sales, it is ending production of my beloved, beautiful, silent Cube.

This is Kurt Andersen in Studio 360.