Somehow, I have managed to avoid revision control systems until recently. I set it up for a typical reason: I wanted to be able to work on my thesis from different computers without worrying too much about keeping different copies in sync. Also, it's nice to be able to keep track of my progress. I don't expect to ever revert to an older version, but seeing a detailed log of changes makes me feel I've accomplished something.
Perhaps it's a good thing I put off learning about version control for so long. Back when I first thought about using it, CVS was the most popular open-source choice, Subversion was immature, and Linus Torvalds didn't use any system for the Linux kernel.
Now a new generation of source control tools has materialized, and are being improved rapidly. Development of the Linux kernel has benefitted ever since Linus started used revision control systems years ago.
So it seems it is a better time than ever to delve into version control. The old systems were plagued with various flaws and annoyances. The latest systems resolve these issues, but I wouldn't know. I never used the older systems so I have no idea what the problems were.
Things have gone smoothly for me with Cogito (basically some shell scripts based around Linus Torvalds' git tool). Even though it's designed to be a distributed source code management tool, it works well for one person editing a few files.
The only problem is that I can't easily host the repository on my Debian-stable server since git is too new, though Debian backports exist. I could just use rsync, but this method is deprecated and highly discouraged. [Also explained in this git tutorial; search for “rsync”.]