Robert Walker wrote:

> Is there a mechanism that can be built or that I could buy that
> would detect that it was not a modem and disconnect my PIC project,
> thus allowing me to talk to the person on the phone.

JDR Microdevices at:

        http://www.jdr.com/JDR/

They have a FAX/Modem/Phone Switch that is placed between the phone line and the
three devices.  When it detects a ring, it takes the phone off-hook and listens
for a tone.  If the tone is a FAX tone, it sends a ring signal to the FAX
 machine
just as though it had come from the phone line and channels Tip & Ring to the
FAX.  It does much the same for a modem tone.  If it hears neither, then it
 rings
the telephone.  It has a bunch of other "spiffy" features.

Pricey at about $90US, and I don't know if it works down under, but at least it
is a lead.

Michael