This is a Firefox 3.* extension that looks very attractive to the researcher that wants to be able to link resources for a project together. I just installed it and haven't even used it yet, but it appears it probably uses an sqlite database for storage. It also integrates with OpenOffice and Word.
check
zotero out here:
http://www.zotero.org/
http://www.zotero.org/videos/tour/zotero_tour.htm - video tour
They are planning network capability for the 2.* release.