I've been pretty lucky so far on the comment spam here until yesterday when the floodgates opened.  To combat it, I've enabled the Captcha feature that requires you to type a confirmation number to be able to post a comment.  It is fairly self-explanatory and should work fine.  Let me know if there are any problems with leaving comments.

P.S. This will most likely prevent using third-party tools to leave comments (like RSSBandit, etc).

[UPDATE] Jen and Dave are having a similar war on comment spam with WordPress.  Her blog software of choice.