As said before, replication is great provided it works. It works well if it's understood and works even better if it's tested. This is a great reason to use repmgr.
repmgr is an open source tool designed specifically for PostgreSQL replication. To get additional information about repmgr, visit http://projects.2ndQuadrant.com/repmgr/.
repmgr provides a command-line interface and a management process (daemon) used to monitor and manage PostgreSQL servers involved in replication. repmgr easily supports more than two nodes, with automatic failover detection.
Install repmgr from binary packages on each PostgreSQL node.
Set up replication security and network access between nodes according to the Setting up streaming replication security recipe.