The BrlTTY application provided by the SUNWbrltty package provides support for
refreshable braille displays connected to the machine.  See the following URL
for an example of what a refreshable braille display is:
http://www.baum.de/en/products/brailledisplay/svario.php

Ubuntu currently automatically detects that a USB braille display has been
connected to the machine.  When this happens, it launches BrlTTY.  This is a
very convenient and high usability thing for the user.  Without this, the user
needs to launch BrlTTY by hand, and this makes us run into a chicken-and-egg
situation if the user needs BrlTTY running in order to start it.

Since braille displays are hard to come by and I have a braille display, I'm
happy to help here.  I'm not sure where to start with doing this, however.  It
has been suggested that the printer detection/configuration utility might be
something that could be a model, but it's a space I know nothing about.  Point
me there, though, and I can start poking.  :-)