1. A method performing a comparative web search comprising: providing a meta-search engine in communication with a plurality of web-based search engines; providing said meta-search engine with a query, a search mode, and a selected set of said web-based search engines, said meta-search engine using said query to search for documents on the selected set of said web-based search engines, wherein the search mode includes the following modes: (a) a comparison of data sets collected from same or different generic web search engines in response to two or more different queries, (b) a comparison of data sets collected from same or different generic web search engines in response to a common query performed at different points of time, (c) a comparison of data sets collected from different generic web search engines in response to a common query performed simultaneously, (d) a comparison of data sets collected from same or different generic web search engines in response to a common query performed in different languages, (e) a comparison of result sets collected from same or different generic web search engines in response to a common query where intra-domain similarity between results of the same set is 100% while inter-geographic origin similarity between result sets is zero, (f) a comparison of result sets collected from same or different generic web search engines in response to a common query where intra-geographic origin similarity between results of same set is 100% while inter-geographic origin similarity between result sets is zero, and (g) a result set retrieved from a generic web search engine in response to a query is segmented into bins of equi-distant and equi-weighted segments and the segments are compared to generate comparative summaries; retrieving automatically search results from each of the web-based search engines in the selected set in the form of at least web snippets or documents from each member of the selected set of said web-based search engines and using the search result as raw data; providing automatically the raw data to a data pre-processing module which automatically removes stop words and HTML tags, and applies a stemming algorithm, resulting in pre-processed data; providing automatically the pre-processed data to a comparison engine, said comparison engine performing an object level comparison or a thematic level comparison depending on which comparison is specified in the search mode, said comparison resulting in a plurality of result sets from the selected set of said web-based search engines; determining automatically logical relationships between each of the plurality of result sets and providing a results comparison of the determined logical relationships; organizing automatically the search results in ranked lists when the object level comparison is performed by the comparison engine and labeled hierarchical clusters when the thematic level comparison is performed by the comparison engine, said organizing resulting in organized search results; and outputting the results comparison and the organized search results for viewing.
11. The method of claim 1 , wherein the logical relationships determined by the comparison engine is an intersection of results common to all of the plurality of result sets, results common to at least one subset of the plurality of result sets, and results unique to each of the plurality of result sets.