I’m not sure about you, but I get a fair amount of Comment spam.
None of it makes it to being posted, since I have to approve every comment - but it’s still darn annoying getting a bunch of emails that I have to log in and mark them as spam.

I found this nice little Wordpress plugin: Timed disabling of wordpress comments, which should help with that - atleast, for older posts anyway.

Anything >= 14 days old should have comments disabled automagicly.
Yay.

Edit: Works too, yay!
Edit 2: I’d thank the fellow who wrote it… but err… comments are disabled on that blog post (funny that), and I couldn’t find an email address. Putting random off-topic comments on his posts about him buying/selling a house, or about his children is… well off-topic and near-spammish.
Hopefully he’ll find this post in his referrals and see these words some time.