Safe Search Sites
Online geography database including kids, states, and world editions.
Kid friendly site for searching for images.
Wonderful search engine designed around Google's safe search. Very nice visual appeal for kids.
Ref Seek's intention is to serve only search results that are academic in nature.
A group of experts, including librarians and teachers, evaluates all content from this search engine.
A great site developed in the UK by teachers who approved everything on this site.
WolframAlpha is billed as a computational search engine and this is exactly what it does.