http://sickbits.net/nagios-deployment-automation-tips-and-tricks/
Specifically with Nagios in the case above.
http://www.linux.com/learn/tutorials/431119:weekend-project-using-git-to-manage-config-files
http://www.networkassassin.com/foss-solution-for-network-configuration-backups/
Great use of EEM to backup config. It would be interesting to integrate Puppet into this setup and have the system receiving the configs first diff to see if there were any changes, then check with the puppetmaster to make sure everything was kosher.