Well, my site has gotten popular with one particular set of users. Spam bots. Im getting about 10 spam comments a day now, but luckily help is here. One of the great things about using Drupal to power my site is that when I want to add a new feature, 90% of the time somebody has already written a module that I can just add to the site. So I have now added the captcha module to the site, forcing users that aren't logged in to answer a simple question when they leave a comment. This should hopefully filter out some of the spam bots. And people who can't do basic arithmetic...