Wikiseek – Search Wikipedia and its external links: An external search engine for Wikipedia. Not sure how this is any better than a site-specific search in Google, but I like the concept
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 Searchme’s category refinement technology, providing suggested search refinements based on user tagging and categorization within Wikipedia, making results more relevant than conventional search engines.
This goes back to my concept of FilterBlogs which I thought was great, but no one else really cared about.