A close reading of my last post reveals that I was confused – when installing PHPPgAdmin on the same computer as postgres, all that needs to be enabled for TCP/IP is localhost (127.0.0.1), not whatever local network you happen to have. This got to be a bit frustrating when I tried to connect to my PostGIS database using Quantum GIS on a computer on my local network – the connection was rejected.
Luckily, the fix was easy. Following this quick walkthrough for enabling remote access to PostgreSQL, I just had to edit one line in my /etc/postgresql/8.4/main/postgresql.conf file, from #listen_addresses='localhost' to listen_addresses='*'. When commented out, it only listens on localhost; when specified to ‘*’, it listens for all connections.
Webmin, looks like a change could improve your PostgreSQL remote administration significantly – when users specify non-localhost TCP/IP hosts, you could check the settings in postgresql.conf.