Thank you for taking the time to answer this question.
I really like your idea of downloading screen shots from (http://www.webdesignerstoolkit.com/). I think I will make a screen shot of two with toolbars added to the brower (seems to me that a lot of users that I know have one of two toolbars taking away about 50px – 75 px from the horizontal).
To answer this question with a css-trick would be to learn how to create flexible layouts instead of fixed. I will learn how to do that too :D
We all learn by sharing what we know