Strange menu? Help!

I've got a client that wants his site to use the following menu with simple rollovers on all the buttons. The only problem I'm running into is how to handle the sub-menu for "Our Work." It's the only menu item with a sub-menu.

http://www.brianwpiper.com/css/menu.jpg

At first I thought about using disjointed rollovers, but then how do I make the other menu items stay up and have them rollover??

Is there a way to do this with javascript or css??

I can always do it in flash, but I'm not a big fan of having site menus in flash...I could always throw a "Site map" link at the bottom for the search engines, but I'd like to try this another way...

Thanks!!