Metacrawler Searches multiple search engines at one time. Returns many sites that broadly match. Some hits are more relevant than others.
Clusty The searcher chooses what sources to search. Results are grouped by category/topic. Less commercial than Dogpile.
Dogpile Searches 14 different search engines, but has become very commercial.
Invisible Web: Provides access to specialized database services, archives and search tools on the internet that have information not readily available through regular search engines.
Librarians' Index to the Internet Internet resources selected and reviewed by librarians. Browse by subject or search contents of the Index.
Google One of the new search engines that ranks pages based on the number of other pages linking to it. Indexes over 1.6 Billion sites. Uses searching tools such as quotes to define queries. Can search PDF files, Usenet news groups, stocks by symbols and company names, maps, phone numbers, etc.
Yahoo Directory organized by subject categories. Sites are reviewed and evaluated by Yahoo! staff members. Fewer matches are returned but they are better targeted to the search terms.
Hotbot Very accurate results with good sorting features including date ranges and domain limiters. Ranks sites by how often they are selected and how long users stay at a site.
Excite Does very broad searches with lots of hits and will suggest related terms for your keywords that can be added to your search. Offers a lot of advanced features including "search for more documents like this one."
Ask Jeeves and
Ask Jeeves for kids Lets you do searches in the form of a question. The kids site is one of the best for children ages 7 to 14.