Bleeding spam

I logged into my email this morning and discovered that I had 40+ notifications of comments to moderate on my blog.  Not one of them contained interesting content.  They were all spam. This is after I set it to moderate comments, so they wouldn't appear until after I'd confirmed them.

I went about the business of deleting them, then started to look at the settings to find a way to cut the flow of spam.  By the time I'd finished, there were 9 more.

So, setting it to moderate doesn't help.  The onslaught of spam is too strong.  Instead, commenters now need to register to post.  I have no idea how this is going to affect commenting -- I'm not entirely certain how, exactly, one registers on this blog.  I've never had to do it.  (Eddie, if you're reading this, help?)