Anyway, according to LiveJournal IP tracking, the spammer's IP address is 22.214.171.124. Looks like this spam utlimately originated from either France or the Netherlands. If anyone's dealt with BlogSpam like this before and has any tips on what I ought to do, let me know!
I've been toying with the idea of removing the ability to post Anonymous Comments in my journal, which would obviously cut down on this kind of thing. Now that you don't need an invite code to get a LiveJournal account, it might be time to get rid of the Anonymous Comment feature here, but I kinda like having it open like this for people who want to comment without actually setting up an LJ account.