There's a great video from one of the PostgreSQL engineers on Google
Video:
http://video.google.com.au/videoplay?
docid=5745755015991749390 . Has a lot of really interesting
information about tuning and scaling PG (specifically 8.1+). It's a
little over an hour long, so get comfortable. It's also 1 of 4 that
are going to be released, though the other 3 are not out yet.
ms