asterisk users - Mar 2006 - Initiate and monitor multiple calls?

I'd like to set up a sort-of follow-me: on a call to a given extension,
I'd like to simultaneously call several different numbers, play them all a
prompt upon answering, and monitor for DTMF digit 1.  I know how to get
Dial() to dial multiple numbers, and I know how to play prompts and
monitor for digits... but I don't know how to mix it all together.  Any
pointers on where to start looking?

Thanks!

-Ken