Comments allowed for registered users only?

This is probably not what you were asking for but you could use the Comment Moderation Plugin (https://wiki.www.ads-software.com/Comment%20Moderation%20Plugin)
to only allow people who have “registered” through email to comment without there comment being held for moderation.
Search the Wiki a bit it may have a more appropriate comment plugin.

This hack might be what you’re looking for. It works great for me.
https://www.ads-software.com/support/10/7663

Chad: you ROCK. I was >thisclose< to deleting WordPress and trying something that’s overkill like php-nuke. Thank you very much for your suggestion. ??