The Web Page Layout Gallery contains 5 very nice examples of various website layout designs and they are offered for free usage. As the first paragraph on their webpage states: “building CSS-based layouts can be a real pain in the *ss.” How very true!
A few other layouts included in this gallery are one designed to be used in a portal with generic classes that handle the appearance of specific portlets, as well as ‘Ruthsarian Menus’, advertised as a very compatible CSS-based dropdown menu system.
There even is a so-called “experimentation chamber”, but I didn’t have the courage to click through to see what specifically was offered there in the way of CSS layouts.