Traditional library web products, whether online public access catalogs, library databases, or even library web sites, have long been rigidly controlled and difficult to use. Patrons regularly prefer Google's simple interface. Now social bookmarking and tagging tools help librarians bridge the gap between the library's need to offer authoritative, well-organized information and their patrons' web experience. This article describes how tagging and social bookmarking tools empower library users and library staff in new ways. This article also describes the various ways in which del.icio.us, a bookmarking tool, can help libraries do practically anything with their data.