After jotting down the structure and design on a piece of paper I downloaded the latest version of jQuery, read some documentation on authoring plugins and started coding. And now, twenty-four hours later, this is the result:
My very first jQuery plugin! ActsAsTreeTable allows you to turn a column in your table into a tree. The plugin has been made as unobtrusively as possible and I have posted it to the jQuery plugin index as ActsAsTreeTable 1.0. To make it as easy as possible to start using the plugin I have also written some documentation. You will also find several examples in this documentation.