Library of Congress Subject Authority - yeah, the one that gives you keywords or subject headings! Click >>Search Authorities<< and use the default settings. Any result with the red button to the left is what you want to use.

aerospaceweb.org - links to a wide range of aerospace-related sites, including aircraft design, spacecraft design, aerodynamics, and aerospace history.

CAD Register - brought to you by ThomasNet, it purports to be your single source for millions of component drawings.

FindLaw - search for laws, cases, codes.

First Gov - your first click to the U.S. government.

GlobalSpec - specialized search engine focusing on engineering and technical information.

Government Information Connection - hosted by University of North Texas.

MatWeb - "MatWeb's database includes thermoplastic and thermoset polymers such as ABS, nylon, polycarbonate, polyester, and polyolefins; metals such as aluminum, cobalt, copper, lead, magnesium, nickel, steel, superalloys, titanium and zinc alloys; ceramics; plus a growing list of semiconductors, fibers, and other engineering materials."

Texas Online - Texas Law, Codes, and Statutes

thomasnet.com - by Thomas Register and ThomasRegional.