I second the capabilities of Time Machine.
While it's not a great versioning system for long-time backup solutions because it eventually over-writes old backups as space on the disk fills up, I use it as a short-term versioning system with great success.
As a musician and artist, I'll often make changes to a current project which I then regret, but thankfully Time Machine has the version of the document from an hour ago. I'm able to pull that one up, take what I want from the old version, and integrate it into the current version.
It's saved my ass numerous times since its introduction!