Zotero users wanting to collaborate on reference collections, or access their
collections from multiple computers might be interested in this post from Michael Rees describing how he uses Windows Live Mesh with Zotero. If you can’t wait for Zotero 1.5, this might be an option for you. Only for Windows devices so far, Live Mesh promises Macs and mobile phones will be supported in the future.
Sharing the Zotero Database with Live Mesh « Impressions Scholarcast