Faceted Metadata Search and Browse
A brief explanation of faceted search, in which users can easily switch between searching and browsing "using their own terminology for search while recognizing the organization and vocabulary of the data." Includes a comparison with traditional parametric search engines, examples of faceted search, and key features of major faceted-search engines. From Searchtools.com.
Martindale's The Reference Desk
An incredible resource containing dictionaries (generic and specific), calculators (16,000+), maps, translators and a whole lot more. This site is hosted by the Univ of California-Irvine Library.