The PostgreSQL port has a collection of "side orders":

postgresql-doc
  For all of the html documentation

p5-Pg
  A perl5 API for client access to PostgreSQL databases.

postgresql-tcltk 
  If you want tcl/tk client support.

postgresql-jdbc
  For Java JDBC support.

postgresql-odbc
  For client access from unix applications using ODBC as access
  method. Not needed to access unix PostgreSQL servers from Win32
  using ODBC. See below.

ruby-postgres, py-PyGreSQL
  For client access to PostgreSQL databases using the ruby & python
  languages.

p5-postgresql-plperl, postgresql-pltcl & postgresql-plruby
  For using perl5, tcl & ruby as procedural languages.

postgresql-contrib
  Lots of contributed utilities, postgresql functions and
  datatypes. There you find autovacuum, pgcrypto and many other cool
  things.

etc etc...

For procedural languages and postgresql functions, please note that
you might have to update them when updating the server. For example,
the "elog" method disappeared in postgresql-7.4, so postgresql-contrib
must be updated along with the server.

If you have many tables and many clients running, consider raising
kern.maxfiles using sysctl(8), or reconfigure your kernel
appropriately.

You should vacuum and backup your database regularly. There is a
periodic script, /usr/local/share/postgresql/502.pgsql, that you may
find useful.

To allow many simultaneous connections to your PostgreSQL server, you
should raise the SystemV shared memory limits in your kernel. Here are
example values for allowing up to 180 clients (tinkering in
postgresql.conf also needed, of course):
  options         SYSVSHM
  options         SYSVSEM
  options         SYSVMSG
  options         SHMMAXPGS=65536
  options         SEMMNI=40
  options         SEMMNS=240
  options         SEMUME=40
  options         SEMMNU=120

If you plan to access your PostgreSQL server using ODBC, please
consider running the SQL script /usr/local/share/postgresql/odbc.sql
to get the functions required for ODBC compliance.