An email to a mailing list led me to remember what is probably the best testing presentation I have seen in a long time. This is Java code, but it should be easy, even easier, to do in Perl.
If someone were to write this module I strongly predict they would be a huge hero! The presentation lasts for an hour, but trust me, if you're interested in testing, particularly in testing the Web, it's mind-blowing. This conference was the Google London Test Automation Conference (LTAC) Google Tech Talks September 7th, 2006.