Documentation for RHEL 5 systems was already available, however CentOS 5 was a little more trixy due to deprecated file content in /etc/sysconfig/rhn
I've added a note on that Wiki site related to CentOS 5 so follow the instructions there.
http://www.labmonkeys.org/systems_management:patch_management:installing_mrepo_on_rhel5
On the upside I now know how to use pdb, which is darn nifty.
