The vim editor is capable of backing up things you change in several ways. Sometimes when you do not want or need to useSCM because the thing you are editing is too trivial, then timestamp indexed backups come in handy.

Here is how to do it using autocommand defined in your .vimrc:

https://gist.github.com/2204193

Of course you have to have backup enabled and I would recommend setting backupdir to a fixed path to avoid doing a mess all around the filesystem.

Here is a slightly more refined way, but for me the first one works just fine.