*) void KIWAY::ExpressMail( FRAME_T aDestination, MAIL_T aCommand, const std::string& aPayload, wxWindow* aSource=NULL );
*) virtual void KiwayMailIn( KIWAY_EXPRESS& aEvent );
*) enum MAIL_T expansion into the brave new world if cross KIWAY_PLAYER communications.

Let the KIWAY_PLAYING begin.....
through well conceived mail from one KIWAY_PLAYER to another.
Get thinking now.  Add a new MAIL_T value, then send ExpressMail(), 
and receive it in KiwayMailIn(), it's that easy.