Tables with opacity which adds a very power-full touch to the look of a page. I simply set a non-moving background in the body, then set a png bitmap with no canvas color and a white box with 50% opacity. This will make the box transparent with the background and totally creates the illusion that you can see through the table. This is a fairly new, but its an awesome addition site which is table based. Click on the other examples too see how different images look.
Trees || Darkness || Mountains || Abstract