The University of Kansas Libraries
The Meta Crawlers and Bots
Internet Search Engine Groupings
Meta Crawlers actually send your search on to several search engines at once and then combines the results on one page according to various relevancy schemes. Also referred to as "bots," Meta Crawlers are a good choice when you need to get a good starting overview.
Dogpile offers a customized list of major search engines and returns query results by search engine grouping.
Vivisimo returns search results categorized, so it is a simple matter to choose the relevant results.
Kart00 displays search results as a visual map connecting related keywords.
Ixquick returns the top 10 results from each of the major search engines.