Web 2.0 has raised user expectations of how electronic assets should be presented. And, as some librarians and other people will tell you, users seem to have fewer skills and less patience for searching and navigating library catalogs. The Web has instilled the expectation that everyone can be a competent searcher, so the online public access catalogs looks deficient when compared to everyone’s favorite search engines, online transactional environments, and application skins. Users now expect search interfaces to be truly interactive: they can select the scope of the search and the selection criteria they prefer. They want to be able to refine and drill into results without repeating the search. They want the information source to retain information about their choices and their search and activity histories.