WikiSeek – Search Wikipedia Pages
http://www.wikiseek.com/

The contents of Wikiseek are restricted to Wikipedia pages and only those sites which are referenced within Wikipedia, making it an authoritative source of information less subject to spam and SEO schemes. Wikiseek utilizes a category refinement technology, providing suggested search refinements based on user tagging and categorization within Wikipedia, making results more relevant than conventional search engines. To search with Wikiseek, start typing your query into the search box. As you type, Wikiseek will suggest categories related to your query term. Simply click on the category that is most related to your query. If you do not see a relevant category, clicking “All Results” will display unfiltered results for your query. Unlike other search engines, Wikiseek does not have a “search” button. Instead, clicking a specific category or clicking “All Results” activates your search. This has been added to the tools section of Research Resources Subject Tracer™ Information Blog.