I back up my switch configurations nightly using a programming language called expect. it logs into the switch and sends the set of commands that send the running config to a file located on my tftp server. For snmp info like contact information, I wrote a perl script that polls my switches nightly and generates an html document that gets posted to an internal website.

That is the hard, time consuming way to do it. Products like Cisco Works and Cisco Network Assistant can be set up to do this as well.