Same as about everybody else:

- eliminate repetitive tasks by writing front-end wrappers. We have several databases to update when we install a new switch, each has a different front-end written by different people. A nice perl script now does most of the work for me.

- logfile watching, intrusion detection. Our pipes are too big for firewalls/IDS's, so we sprinkle a few logging ACL's for special IP's, and a perl script watches the logs for hit's on those filters. Then it adds a 'watch everything' rule to the ACL for the suspect IP, logs all of it's attempted connections, trys to figure out if it's dangerous and sends email if a threat is found.

- GAMES!! I have about 90% of a Quake3Arena master server written, all in perl. And try writting IRC bots with Net::IRC, amuse your friends.