MT-Keystrokes: This isn’t a bad idea. This plugin counts the keystrokes entered in the TEXTAREA for the Movable Type comments form, and sends that number with the comment. the plugin does some arithmetic on it to make sure it roughly matches the number of characters in the comment.
Based on the experiments of Simon Goodway, it seems that a simple way to reduce comment spam without affecting the reader’s experience is to make sure that every comment has some level of human input.
Obviously, if you paste something into the field, you’re either going to have one keystroke (CTRL-V method) or none (right-click method) in exchange for a lot of characters, so I imagine this plugin has to be a little forgiving since people tend to paste URLs rather than type them.
Good idea, but I’d like someone else to try it first. Found via the consistently good LifeHacker.