BBC.co.uk/news like JQuery top horizontal menu

BBC.co.uk/news like JQuery top horizontal menu

Hi all - first question (probably of many!)

Basically, I'm trying to create a menu and would like to include a MORE button similar to how it is on the BBC website: http://www.bbc.co.uk/

If you click more, the page moves down and a DIV is shown. I wanted to ask:

a) is there a plugin to do this?
b) are there any similar examples out there?

Any help appreciated!