Despite the ever-ballooning size of the World Wide Web, which some experts claim is on the order of 550 billion Web pages, much of the most interesting and valuable content remains hard to find. The best search engines, such as Google or AltaVista catalog about 1.4 billion Web pages, or less than 1 percent, barely skimming the surface of the entire Web. CNN.com —Search Engines Grapple with Constant Web Growth