Richard Padley – Integrating taxonomies with search:

"Alongside a set of search results a search engine can provide a series of drill down categories which allow the user to refine their query and cut down the result set until they find the information they need. If properly structured faceted taxonomies have been used to tag the search documents then the terms from these taxonomies can be used to provide the drill-down categories for the search engine."

(Via all things cataloged.)