Phil Bradley's weblog (a new one for me -- "Where librarians and the internet meet: internet searching, Web 2.0 resources, search engines and their development") collocates a comprehensive list of "370+ Search Engines to explore," both categorized and with a "Which Search Engine When" page and pull down.
. . . There's more to search than Google. If you have time, please take a look, and consider trying out some new ones. You can access them all via my 'Which Search Engine When' page and pull down menus, but here's an overview.
- Key search engines - Free text, Index, Multi, Visual, Categorised, Blended. (41)
- Site based engines - Comparisons, Re-ranking, Site information, Similar (30)
- News search engines - News, Trending (33)
- Types of data - Thumbnails, Overviews, Factual, Hidden, Fileformats, Local (41)
- Types of user - Children, Trusted sources, Academic (48)
- Multimedia - Image, Sound, Video (63)
- People based - People search, Blogs, Forum, Social, Moderated, Bookmarks (82)
- Miscellaneous - Spelling, words, really odd (38)
Alternatively, or as well, I have a general collection of 170+ web search engines that is a bit of a miscellany, and most of them are available in the other lists, but not all. . .
See story link for individual links above.