At the end of October I temporarily reactivated word verifications for comments here on the blog. Spambots were hammering several older pages without mercy, and I thought this action would give me a brief respite and the bots might move on. Seeing a post on G+ today about captchas reminded me that -- since it's been more than a week -- it was time to discontinue verifications and open the comments again.
Blogger is excellent about automatically purging the spam messages. Notifications still get sent to me, and I'll continue to keep an eye on them. There has to be a better way to deal with the 'bots than to inconvenience real blog readers.