If you are a site designer, or a site owner, you will at some point need to evaluate a site. Do the bones of the site stand up, or it is a screaming wreck hidden behind a pretty facade? The first thing I do is look at the source code. Beautiful code isn't the final answer on site testing, but it's a place to start. Is it table based, or a CSS layout? A table based layout should put up a warning flag. Table based layouts are outdated... you can do better. You want CSS. It's more adaptable, and more accessible to a wide range of technologies.