Is there a mailing list for CA-Clipper users on the
 Internet or Bitnet?  Fidonet?  Others?

 Yes.  You can subscribe by sending the message "SUBSCRIBE CLIPPER
 Your-Name-Here" to <LISTSERV@BRUFPB.BITNET>.  Send administrative
 requests to <LISTSERV@BRUFPB.BITNET>.  When you join the mailing
 list you will be emailed instructions on how to post contributions
 to the list.

 On Fidonet, check the CLIPPER echo.

 There is also an active CA-Clipper echo on the cozier but
 lesser-known GT Power network.