How to get output devices to appear in PulseAudio?

[Chris Green]

I am slowly getting to understand what's going on with sound on my
little Acer Revo.  However I still *don't* understand why sometimes
PulseAudio can see some output devices and sometimes it can't.

When it has no output devices not surprisingly I can't get any sound out
of it, I then curse it for a while, run various things to see if I can
understand what's going on, and at some point it works - but I can never
understand why!

So, how does one get output devices to appear?  Then, further, how does
one do this from the command line, because I want to run this headless
and will only have ssh access.  (Running X remotely doesn't work with
modern applications as they use DBUS which breaks X)

-- 
Chris Green