Install pgAdmin III on CentOS 5.5 in 3 Steps

In 3 simple steps:

1. Install epel

rpm -Uvh http://download.fedora.redhat.com/pub/epel/5/i386/epel-release-5-4.noarch.rpm

2. Install rpmfusion repel

rpm -Uvh http://download1.rpmfusion.org/free/el/updates/testing/5/i386/rpmfusion-free-release-5-0.1.noarch.rpm

3. Install pgAdmin III

yum install pgadmin3