I don't know exactly when it happened, but it happened. Almost no one is using the 640×480 resolution on their monitors anymore. I say almost because I know of at least one person that still uses it, and he is a moron.

By far, the most common screen resolution in use today is 1024×768. The numbers for resolutions higher than this continue to grow every day. Why is it then that way too many websites (and themes for common web site applications) are optimized for 800×600? I mean, 800×600 was the most common resolution for a very short span of time. Judging from my research, 1024×768 will eventually be relegated to an uncommon resolution as well.

Web site designers, I have advice for you. Stop using fixed-width screen designs and start using fluid-width screen designs. Test your displays in higher resolutions as well as lower resolutions. It's the simple way to future-proof your designs. Oh, and if you need help, get the Web Developer add-on for Firefox and test with the resize option frequently.

That is, unless you LIKE to reinvent the wheel over and over?