teramongerIn addition to doing what it's supposed to do, the "Elevate Parent Category Template" plugin has some nifty functions that made what I was trying to do, much easier. Specifically (see the plugin's readme.txt) "get_category_child()" which returns the current post's child category ID and "get_category_title($id)" which gets the title of the category that is $id.
In addition, the code is very tight and readable and definately worth a look if you are trying to get your head around hacking WordPress.
http://wordpress.org/extend/plugins/elevate-parent-category-template/
