How to Debug your web site on Safari
I've always had trouble debugging layout problems on Safari. There is a hidden "debug" menu on Safari, but it almost completely useless, especially when compared to something like FireBug.
Today I found that if you download the latest version of webkit, which is the open source Safari implementation, there is a visual DOM inspector thing that is really what you need. You right click on some page element, and select "Inspect element" then you get a nice DOM browser with highlighting, and details on CSS info, etc.