Just curious, do you visit the site frequently while maintaining it? Is your resolution set to 1024x768? Some times the webmaster may be the one skewing the results, making it look like the majority of the users view the web page as you do.

We also might want to take into consideration that just because I have my resolution set to 1024x768, doesn't mean I have my browser maximized. I rarely surf with the browser maximized. It all depends on how the window opens when I click my browser icon.

You also have users which surf with side panels open (Favorites, History, etc.), which takes up screen space.

I personally still design pages at 640x480, but allow them to stretch for people with higher resolutions. Not only is this good for people with 640x480 moniters, but for those who want to print out one of your web pages. Most printers only print 650px of screen space. (Not including landscape mode) The rest gets cut off.

And I don't accept the paperless society excuse. A lot of people I talk to use more paper now than they ever have because we are going paperless.