Update 2007.10.13: Hydroponics spam continues. Comments remain moderated. Permanently, I suspect.
Update 2007.10.10: Today it's hydroponics spam. Comments remain moderated.
Due to Costa Rican spammers (you don't want to know), I have to temporarily enable comment moderation for the blog. In compensation, I've also temporarily turned off word verification (CAPTCHA) for new comments.
They're following the usual spammer pattern: they target posts that are at least a year old, put in some boiler-plate text about "how wonderful your blog is", followed by a link to the spam site. Easily recognizable, but a pain in the @$$.
We'll see how long this takes to settle down ...