AllPlus (metasearch, cluster)
DuckDuckGo (anonymous)
Mashpedia (real-time encyclopedia)
Dewey Digger (a DDC browse)
DocJax (search for documents)
Secret Search Engine Labs (alternative search results and open algorithm)
Bing Visual Search refine queries through selecting images
Browsys (search across the search tools)
Search Cube (visual page search)
Wiki.com (for searching wikispace)
Findhow (How-Tos from Names You Trust)
Clusty (clustered search)
Leapfish (combines Google, Yahoo!, MSN results)
AllMyFaves (choose you search tools among a bunch of categorized icons)
Kartoo (visual search)
Twurdy (results ranked by reading level)
Kosmix (Results organized by types of Web results--reference, media, conversations, news & blogs
Soople (busts out Google's features)
Wayback Machine (archived web pages)
Ms Dewey (a librarian guides your search)
Boolify Project (an educational boolean search tool, currently in beta)