I am not a DBA; I\'m the primary developer of an enterprise database based application.
I\'m currently specing out some new machines to upgrade our existing enterprise
The PostgreSQL 9 documentation gives a nice overview of the options available.
http://www.postgresql.org/docs/9.0/static/different-replication-solutions.html
You might want to look at Slony if you do not mind having to write to the master and not the slave, or if you want, check out any of the multi-master replication technologies available.
pgpool-II can handle this for your:
Check this example.