I know lots of people hate the "captcha" words you have to type in to prove you're not a robot. But I had to turn them on to avoid the sheer onslaught of spam comments I got. I don't know if the bots stop sniffing around a blog if it has word verification, if they will come right back without it, but I turned it off for a while.
So if you hate the captcha words and have been avoiding commenting because of them, now's your chance. For a while, at least. If I get hammered again with spam, back they go.
(I wish blogger hadn't eliminated a functionality they used to have: where you could close comments for posts older than some time frame - I think 30 days was the default. Most of the really annoying spam I was getting was on old, old posts. I could co back and manually turn off commenting on those posts....but I have something like 8000 posts and it's so not worth the time.)