Grant Barrett nails it in his assessment of the New York Times’s redesign, in which one major decision was to bust the screen width to 1000 pixels: “Hey, who said we read (or want to read) ANY web site with the browser window filling the whole screen? The only people I know who do that are n00b Windows users.”

Mind you, the Times is simply keeping up with the joneses. Many of its peers, from the Washington Post to the forward-thinking and usability-centric Cnet to the wise folks at The Economist, have expanded their screen sizes, largely to capitalize on ad revenue and space above the fold. (Full disclosure: I commended The Economist on its redesign in this space last fall, albeit with the same point I’m about to make.)

But I’m with Grant on this one. Thanks to years of Mac use, my browser windows are never set to full-size, even when I’m on Windows. Reading studies for years have said 450 pixels is the maximum optimal width for reading text, even if some people train themselves to do otherwise. Most importantly, between 25 and 30 percent of Internet users are still on 800×600 monitors, a significant audience segment.

Yet the push for real estate nudges design ever wider, regardless of the consequences—and, perhaps, the realization that a quarter of the viewing audience won’t even see the right-hand side of the screen.

My department at work just finished an audit of two dozen ecommerce websites in our competitive space. Of them, 23 had fixed-width designs between 700 and 800 pixels. The one with full-screen capability stretched its header and footer without altering the content-and-commerce area. Clearly, the optimal usability level is not yet at 1024 pixels in width.

Colleagues at magazine websites have told me their wide-screen ad space performs well, so I won’t argue against it. But I won’t argue for it, either.