Wow. Over the past week (to the second), my new system for excluding comment spam has blocked 2329 comment spams — and a scant few accidents of addition, of course. That’s astonishing to me, particularly since I use my own comment scripts, rather than any of the standard comment systems. Happily, my new system has caught every last little bit of comment spam. In retrospect, my old (regex) system was working amazingly well, since it only allowed a few spams out of that barrage to be posted. Still, I vastly prefer none to even a few.
Many thanks to Kyle Haight for the suggestion of fooling the spambots with arithmetic! (Since it only took about five minutes to implement, it paid for itself in the first day!)