MT-Close2 is a plugin to close old entries to comments and trackback.

Via this useful site, which includes a host of other promising links such as a trackback-script-name randomizer. So far, I have not found links to references about an approach which an unnamed smart person shared with me sometime last month. I think of it as the spam-fighting tactic Which Must Not Be Named.

Learning Movable Type, the site that hosts the resource page above, looks interesting to poke around.

For best effect imagine me waving my hands around as you read the next sentence

But dang, I don’t have time to dink around with this stuff anymore!