iGoogle is a customisable homepage that allows users to add "Gadgets" for a variety of purposes. Many libraries are already offering gadgets for use on iGoogle, Google Desktop as well as syndication on any Web page.
LibX is a Firefox (soon for Internet Explorer, too) extension that provides contextual linking to Library resources. As all the work is done in the Web browser, individual Web pages do not need to explicitly support LibX.
Zotero is another Firefox extension for bibliographic management, a la EndNote. References can be saved to a database and then inserted into Word documents using any one of a number of different referencing stylers.