>The standard is now 800x600

As Sylvain said, maybe for you. In general there is no standard, we have everything from 14" to 21" monitors, and you will probably find about equal numbers of users with 640, 800, and 1024 settings, partially but not entirely a function of monitor size. Some people with 19" still prefer 640, if they're farsighted or something. So you almost always have to program at 640, and if you have time, build in a resizing mechanism to your app.