I think I've removed over 100 spam comments from my blog in the last 48 hours. I'm a little tired of it, so I added a few obvious words to my word blacklist and then I went and modified the comments plugin to allow for "draft" status.
Then I wrote a small script that goes through the directory, finds all the comments in draft status, prints each comment to the screen and asks me what I want to do with it. That'll prevent comments from getting published without my manual approval.
It's funny to note that many/most of the comment spam are comments on my entries on comment spam.