So Close, and Yet...
So it turns out that vorlon does allow CGI scripts, but it doesn't appear to support any means of redirecting URLs to them. So on one hand, I could set up a dynamic blog which would allow comments, and that would be cool. But on the other hand, my blog would be at vorlon.cwru.edu/~sbm5/cgi-bin/blosxom.cgi, and that's much less friendly.
So for the time being: no comments. But hopefully I'll come up with a clever solution.