An answer:Google Desktop Search.

Not only is it incredibly easy to set up, installing the correct plugins will give you a simple versioning system for all your projects files. I'm unsure as to the number of cached versions GDS will store for a particular file, but I'm at 8 already, and you presumably won't need much more than that for a single person project. Oh well, this is probably incredibly old news, just thought I'd share it with you guys :)