Personally I have written a small web-application to help me play travian. I setup a cron to download the game provided sql file, load it in, and keep the last two weeks worth of history.
Then I use this to find players that are inactive, or smaller than me, and take their resources. After a while I had some trouble keeping track of who I attacked and when, so I added in fields to keep track of last attack, the bounty from the attack, losses, and if there was more still to steal.
Now I just query the database for those who: I haven't attacked yet today or still have resources left to steal, sorted by last bounty (largest first).
This isn't against game rules, however, if there was a site offering this type of functionality to all users, I would suspect that my nice sql file might go away. I am not terribly worried about this, since the amount of calculations I am doing can get quite taxing on my little box. I know it won't scale well without serious refactoring.
So tell me, what is the most 'recreational' use you have for Perl? It doesn't have to be a game, it just needs to be somthing you have written in Perl to allow you to have more fun.