I saw this web site once, and on the enter page, it asked for you to choose your "flavor" and there were 4 buttons, each one labelled something
ex:
angel
demon
snow
flowers


depending on which one you would clik, it would bring you to the site but with a different layout (depending on the button)..
so all those buttons linked to the same site, except they all had a different layout (all the same size and position, just different colors) is there a simple way of doing this?

Easiest way might be to have the separate pages for each theme that you want, and that would be made even easier if you use SSI or PHP.
If you can use PHP there are scripts you can use to theme the website, like this one: http://domesticat.net/skins/howto.php