reCAPTCHA
/I've updated some of the software that drives this blog, so you can now post a comment without creating a username, as long as you solve the reCAPTCHA to post it. If you get one that you can't decipher, click the two arrows chasing each other to get a different one. If you're a registered user, you'll only have to solve one reCAPTCHA, at the time you register. I'd initially disabled un-registered comments to avoid spam, but was still getting registration spam. Hopefully, by using reCAPTCHA, both problems have now been solved!