Just a simple accordion driven menu with sublevels.

This simple menu has a neat effect by hovering over the links, and opens a submenu with an accordeon.

The mouseover events will make the text upper case and change background image. Submenu items are differentiated by font color and an image appearing on the right. Vice versa, when releasing a button the text will be lower case again.

Of course you can have even more mootools based submenus – just look at the code and play around.