As you can read, I've been traveling around quite a bit lately. This means I haven't been checking the comments on my blog, which means quite a bit of spam has been entered. I am blocking the spam via akismet, however, it is still recorded in the database. Being somebody who hates cluttered desktops, you can imagine how I feel about having a lot (447) of spam. Well, since akismet flips the is_public switch True for good comments and False for bad comments, that makes a really easy query in mysql.
mysql> delete from comments_freecomment where is_public = False
Of course, make sure you have backed up your database first.