JavaScript Source: Navigation: Category Menus Demo locked to the height could be worked with seems fairly cross browser

Dynamic Drive DHTML Scripts- Contractible Headers Script Description: A script that makes selected headers in a page contractible. Contents such as text, graphics, tables etc can be hidden inside the header that will be revealed only when the header is clicked on. All other browsers, including NS 4.x, will simply see the headers uncontracted (degrades well)

Dynamic Drive DHTML Scripts- Smart Folding Menu Tree Description: A folding menu tree that contains links and sublinks. Click on the folder icon to expand it. Browsers apart from IE 4.x will see the tree fully expanded (degrades well). The menu supports arbitrary nesting of sub-lists, and? uses session cookies to give it persistance. In the past, whenever you opened a folder and clicked a link inside, when you returned, the folder reverts back to its initial, closed state. What a waste of time of having to reopen the folder(s) each time you return to view the links inside. Using cookies, this "smart" folder script will actually remember the state of the folder tree when you navigate to another page, so when you come back, it will look just the way you had remembered it to be. If you can't appreciate this feature, you can bet your surfers will!

Dynamic Drive DHTML Scripts- Top Navigational Bar II Description: One of the best of it's kind, this is Mike's two-level menu bar script. Use it to intelligently organize your site's links while adding a touch of DHTML coolness at the same time. Wonderfully useful and cool a creation this is.

Dynamic Drive DHTML Scripts- Slide-In Menu Bar I Description: A cool menu bar that automatically slides open from the left edge of the screen as the surfer moves the mouse over it. Moving the mouse out will cause it the bar to slide back in. Browsers other than NS 4 and IE 4 will simply see nothing.

Cut & Paste Folding menu tree (Requires IE4 / NS6 ) Description: A folding menu tree that contains links and sublinks. Click on the folder icon to expand it. Requires IE4 or NS6 , although all other browsers will still be able to navigate around.

EVHEAD! cool nav bar check it out!!