For a long time, Dominus ran a perl quiz of the week, http://perl.plover.com/qotw/. He hasn't had time to do so for some time, but volunteers have occasionally posted quizzes to the unmoderated -discuss list. I posted one today, and hope others may join in and keep them coming more regularly.

Update: solutions should be submitted to the list, but only beginning 60 hours after posting of the quiz to allow people time to attempt it before seeing other's solution.