These are older tips I wrote for TechRepublic but I found myself needing to look them up before and realized they weren't linked on my blog. Of course, with over 200 articles written for TechRepublic over the last 7-8 years, that's not surprising. =)
Anyways, Automate configuration backups with subversion is a quick way to use subversion to track configuration file changes. It can be retro-fitted to work with anything really, but the sample is for committing and tracking changes to /etc/ in subversion. I use it on all of my servers; it's awesome.
Another subversion-related tip is Automate subversion backups which goes into handling automatic backups of subversion repositories. Having experienced subversion corruption (once only, thankfully), I find this is a great way to ensure you have a working backup of subversion at all times. It's a little brief, but does the job. I've expanded on that to also dump single commits every time they're made so you have an outside-of-svn-constant-backup of stuff that can be used to reconstruct the svn repository easily.
Anyone who knows me knows that I'm overly cautious and almost anal when it comes to backups of stuff. =)