Ever wondered how to do the Increase/Decrease font sizes without reload…?

 $(document).ready(function() {
    $("a.Styleswitcher").click(function() {
        $('link[rel=stylesheet]').attr('href' , $(this).attr('rel'));
    });
}); 

Then put the links somewhere prominent, most likely chganged to images.

    Default Theme
    Red Theme
    Blue Theme