Setting up postgresql for rails on Snow Leopard

First, install macports if you haven't already.

sudo port install postgresql84 postgresql84-server

sudo mkdir -p /opt/local/var/db/postgresql84/defaultdb

sudo su postgres -c '/opt/local/lib/postgresql84/bin/initdb -E UTF8 -D /opt/local/var/db/postgresql84/defaultdb'

sudo launchctl load -w /Library/LaunchDaemons/org.macports.postgresql84-server.plist

sudo su postgres -c '/opt/local/lib/postgresql84/bin/postgres -D /opt/local/var/db/postgresql84/defaultdb'

sudo env ARCHFLAGS="-arch x86_64" gem install pg

createuser --superuser macusername -U postgres

Where macusername is you username on your mac. That should do it. Install pgadmin if you like.