>some easy way to support an NNTP
>newsgroup =
>server with the traffic on a Listserv list.

You would need an NNTP gateway. I seem to
recall one at American.edu??  But I don't know
of one now - SPAM and bandwidth may have
become overwhelming problems.

Or, try Lyris, another mailing list product that does
NNTP and Web access as an adjunct to mailing
lists.