Let me preface this by saying that the methods used in creating the tabs below are nothing terribly revolutionary or original -- but merely are demonstrated to share the idea.

I came up with these little "mini tabs" for navigation while working on a few projects. They'll probably appear in the real world eventually. They are generated with pure CSS of course, and require no images. A neat little pop up effect for a selected navigation item:

Tested in Camino, Safari, IE5/Mac, IE5,6/Win. Take a peek at the working example and code if you are interested.