Unfortunately, I had several waves of spam comments on my blog. Turning Word Verification on did not help, nor did the requirement to have a Google account help. So I was unfortunately forced to turn on comment moderation. In short, that means your comments no longer appear instantaneously, but only after I was able to review them. I know this is a bad thing, but I think it is better than turning off comments at large.
I have also temporarily hidden all comments. This is so that I have some time to clean up the mess. Once this is done, I will re-enable all valid comments.