Smooth Sliding Navigation Bar
The smooth sliding navigation bar can also be used for a vertical "side" nav bar, the sub menus can actually slide up down left or right. The speeds, sizes, delays, and almost anything else you can think of can be modified to suit the needs of the site. The page can also be stylized so that if JavaScript is disabled the menus will still be usable.
Now what if you wanted an item to expand or collapse and stay put instead of moving back automaticly (for example: hideable page sections, expanding submenus that dont auto retract, etc). JavaScript handles that on the next page.