So, I've got confirmation (thanks tron!) that auich(4) with AC97 modem
codecs indeed can go off-hook and play/record audio over a phone line as
long as your modem codec isn't made by Conexant.

I've got a Conexant codec, and I'm vacationing for a week, so I won't be
working on this over the next little while.. but who wants to give me a
nice present for when I come home? It would be great if we got
slmodem-2.9.9b up and running on NetBSD to the point where we can do PPP
over it!

So, beer for whoever mails me a patch first for slmodem-2.9.9b using a
dial-up account, connected through auich(4) and PPP on NetBSD. You have
to come to Saint John to pick it up though ;)

Cheers, and see you all next weekend,
Jared