I had to jump through a small hoop to install the postgres gem on Snow Leopard so I'm putting it here to help others out. Hopefully it saves you some time.
- Ruby 1.8.7
- OSX 10.6 (Snow Leopard)
# sudo port install postgresql84-server
Install the Postgres Gem
# sudo env ARCHFLAGS="-arch x86_64" gem install postgres -- --with-pgsql-lib=/opt/local/lib/postgresql84 --with-pgsql-include=/opt/local/include/postgresql84