You can find more information on the speaker's site:
Make Apache bend to your will! We'll look at two ways to have fun with apache and mod_perl.
First, we'll see how to write a simple Apache2 module that acts as an output filter (munging text in certain pages) according to parameters from your Apache configuration.
Next, we'll look at a more drastic modification - changing Apache::Registry itself to add some new behaviors, such as sending an email when a perl script dies.
This topic is based on modules developed at the Sol Genomics Network, http://sgn.cornell.edu. Attendees will be encouraged to adapt these techniques for their own nefarious purposes.