jquery menu with scrolling

I want to build a vertical menu bar like

http://users.tpg.com.au/j_birch/plugins/superfish/#examples

But on the mouse over I need to sho开发者_开发知识库w more that 15 up to 20 items. So I am thinking of it would be good if I show 5 items initially and provide a arrow at the bottom of the items, so on the user click I can show the next five items. Is there a menu plugin for that.

Thanks.

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I think people will find that annoying... why not make it wider and have columns in the pop-out column like ebuyer has?

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Such scrolling menus are among the most horrible piece of UI ever invented. Please do your users a favor: Avoid it at all costs.

Why not have multi-columns menus instead? Or organize the choices in submenus. Although this is fairly horrible as well.

I second Ian Barker's solution: I find the ebuyer solution very elegant.