Scrollodex is a jQuery plugin that presents a new approach to having tables with a scrolling body. Traditionally, you would need to have separate tables for the head and body, wrap the body in a width a fixed height and overflow: auto... but this is problematic on so many levels. Scrollodex instead toggles individual rows in the table to give the impression of scrolling.
You can check out official demos and documentation at http://jquery.kuzemchak.net/scrollodex.php
Please note: As of 3/9/2009, Scrollodex is no longer being developed or supported. If you wish to continue to use it, you are more than welcome to, but be aware that it will only work properly with jQuery 1.2.6 and jQuery UI 1.5.3.