asterisk users - Dec 2004 - Q: How do I join an in-progress Zap channel call?

Folks,

	What is the canonical way of joining an in-progress Zap channel
call?  I already make use of the ZapBarge command to monitor calls in
progress, but also want the ability to join a call in case I have an
important message to pass along to one of the parties.

	It seems that the basic functionality is already in place (via the
MeetMe conference bridge), but I'd like a command which I can invoke in the
dialplan (a la ZapBarge) to bring everyone together.

                                        Cheers,

                                        Rob