Here is an interesting plugin I found by chance when reading Eric Meyer’s blog. So what does it do?

This plugin will notify commenters when their comments are caught as spam by Askimet or put in the moderation queue.

You don’t get it? well, say that you have a lot of spams going on on your blog, they’re all efficiently caught by askimet so you never check them in your admin dashboard. But sometimes, among them, you have a real comment from a real commenter. You’ll never see it or be aware of its existence unless the author knows that he’ll have to notify you that his comment is in your spam folder. And that’s what Antispam Collateral Condolences does. As a bonus it also tells commenters that their comment is being held for moderation. Thanks to Mark Jaquith for developping this nice plugin.