As many of you may have already noticed, spam bots have a tendency to target older posts in hopes of flying under the radar. Whether these spam comments are left by a bot or by a human being doesn’t really make all that much of a difference: they’re still a hassle. Sure, Akismet picks up on most of the spam comments on most blogs, but there are still a few that manage to squeeze through the cracks. As your blog gain in popularity, you’re probably going to get bombarded with an exponentially increasing number of spam comments.

Thankfully, there are at least two plug-ins that can address this issue directly. Comment Timeout by James McKay is designed for WordPress 2.x blogs and it comes with all sorts of cool features. At its core, it gives you the ability the automatically lock comments on posts that are older than a certain number of days. You can set this number in the options. You can also designate posts on which you want to leave comments open indefinitely.

Some people may be concerned that they are ending discussions too quickly with a plug-in like this. Thankfully, Comment Timeout addresses this issue too. If there is a post that meets a pre-determined number of comments, it is automatically considered “popular” and the comment form will be left open for an extended period of time. Other features include the ability to send comments on older posts to moderation (instead of closing comments altogether) and the ability to warn users when a discussion will be closed.

If you’re looking for something a little simpler, there is also the Auto Shutoff Comments plug-in available at WordPress.org. It’s nowhere near as fancy as Comment Timeout, but it still gets the job done.