> Here's my problem. I have a 14.4 kbps modem and use SLIP. Currently,
> I cu at 19200 baud, then exit and slattach at 19200. That works,
> insofar as I can do pretty much anything with the net.
> 
[...]
> 
> If that's not feasible, or even if it is, could someone also
> tell me if/when the gurus are planning to add support for
> flow control?
> 
> Thanks :-)
> 	-Ben

Did you try 
     slattach -h -s ...       
-h like hardware handshake ?

For me this works fine even with 38400 Baud between Mac and Modem.
If you already tried the -h switch, check you modem cable.
With my cable I had to connect HSKO (Handshake out from the Mac side)
to the RTS pin (pin 4 in a 25 pin D-sub connector). The original cable
had a connection from HSKO to DTR (pin 20 on D-sub connector).
HSKI should be connected to CTS (pin 5 on D-sub connector).

Hope this helps
  Walter
-- 
EMail: walter@ghpc8.ihf.rwth-aachen.de   | SnailMail: Walter Ruetten
                                            _o        Turmstr. 190
Phone: ++49 241 807945                   _`\_<,       52064 Aachen
Fax  : ++49 241 8888213                 (*)/'(*)      Germany
  "History --- an agreeable set of untruths"  -- Powhiri Rika-Heke