Other PyBlosxomers have been nice enough to listen to my various gripes about plug-ins and extras, and to lend a hand (thanks guys: that was quick).
Ted Leung rolled in the various changes to trackback.py that I'd accumulated from various other hackers. If you use trackbacks in your pyBlosxom install, get the latest from ted's site. Looks as if he also has an updated version of commentAPI.py, so I copped that. He added a plug-in, xmlrpc_pingback.py, but I wasn't sure precisely what it did since it didn't have the standard plug-in doc header. I may pore through the code when I get a chance.
Eric Gaumer put a lot of work into the autoping plugin. He hasn't released his patched version, but I'll look out for it soon. He tried to use it to ping back my site, but apparently my trackback/pingback RDF was wrong. I think I've fixed it. If you try to ping Copia through a comment URL and it fails again, please let me know.