LiveJournal Valentine System
What I created is essentially a database based double-blind system.
You nominate (up to) three LiveJournal users, and if any of those nominate you back you're both sent a nice "You have a Valentine match" email.
This is the first time I've used the Perl DBI to interface with MySQL, previously I've used PHP.
I have to say, though that it rocks - very simple to understand, and very easy to work with. Kudos to the Perl DBI people.
So .. if you're a LiveJournal user give it a go: