He has a "Pie filter" for Balloon-Juice (it replaces text of user-selected trolls with ranting about pies) that works really well. It uses Greasemonkey and similar tools. It seems to be a fancified version of the CSS that some masters were using here back in olden times, but it's got buttons and stuff and is very easy to use.

http://ok-cleek.com/blogs/?page_id=19041

Looking at the script may give you some ideas.

Cheers,
Scott.