Here's an example of 2 skins.

Check out www.dashpoint.com -- I applied a skin that changed the whole look and feel of my web site to look like microsoft.

Next take a look at www.purdyplayground.org this is the same portal code with a different skin applied...

Here's a couple of articles on skinning:

http://www.code-magazine.com/Article.aspx?quickid=0401051

http://www.code-magazine.com/Article.aspx?quickid=0503091

Rodman