Comment Spam

As the blog gets more popular (yay!) I'm getting increasing amounts of comment spam (boo!). I installed the Mt-blacklist plugin, but I don't update the list religiously and as far as I can tell it doesn't update itself. And the things that got through today (e.g. http://www.drugsexperts.com/ and http://hair-loss.hair-loss-cure.net/) were not on my five-day-old list. Is there some way — even a chron job? — to pull down a master list somewhere Out There and automagically merge it with my existing one?