From what I understand, if you use the Zotero Standalone (I'm new to this and have never used the Firefox add-on), the program will automatically sync, and backup, every few minutes. If this doesn't happen for you, then check the options and preferences under the sync tab. I have over 1.4 gig of 6000+ entries in this project backed up on my local drive!
Thank you everyone invovled in this project. I actually started my own group in Temple University for shared Buddhist studies bibliographies a few weeks ago before I found this great resource.
-Kin