Reid Burke has started a project called yodeler which sets out to create a new set of extensions for YUI. His most recent extension is a tab view which allows the content of each tab to scroll horizontally or vertically:

My first offering is an extension of YAHOO.widget.TabView that uses a scroll animation to transition between tab content.
It works just like TabView, except you must specify a width and height for the parent container in the attributes. All styling is done automatically!

ScrollTabView.js is released under a BSD License and is available for download via Reid's SVN repository