Spam Blocking….

I have version 1.2.1, and what I’m interesting in trying to find out is if there’s any possible way of blocking comments that meet criteria spam words list. Reason being is, while yes it’s nice to still force those into a holding queue, it starts to become quite tiresome to have to delete 20-30 comments a day created by a auto-commenting bot…
Is there a plugin or a hack to change this? I’ve been searching the forums and wiki to see if there is but I haven’t ran into anything yet…