Does anyone know of any new developments in MOH/Netwaiting programs for Linux?

I've got this nice, expensive USR 5686E and now I have call waiting. I was hoping that this setup would at least do what my Mom's old Win95 box with a call-waiting modem does - make a ringing sound when a call-waiting call comes through. But nothing. Linux is not supported by USR for its ICN application and I have yet to find any generic MOH application for Linux.

Hopefully soon? Having to drop offline every so often to check voicemail really sucks...