CAS -The most comprehensive source of chemical info.
arXiv -Many scientific articles. Operated by Cornell University.
ChemIndustry -Chemical site
CI -Corporate Intelligence, 6MM US patents, going back to 1790! 
COS -Searching in expertise, facilities and inventions.
Delphion -Patent search. 
Derwent -Search drug/ biotech abstracts and world patents.
EESE - Engineering E-journal SE, over 100 engineering e-journals.
IBM -IBM's Patent Server, search technology showcase. FREE!
Joe Farmer -Agriculture and farm SE.
Knowledge Express -
Leeds -22 million documents, including patents.
MathWorld -"The web's most extensive mathematics resource."
Novelint -Enforcement, litigation, & licensing for infringed patents.
Pasteur Institute -Search page. 
PubSci -Physical Science Literature, FREE government search!
RAM -Recent Advances in Manufacturing, 500+ journals
Questel-Orbit -French Telecom db for patent and scientific searching.
SBIR Research Center -Commercial site about govt SBIR grants.

ScienceWorld -Growing.
Scientfic Frontiers -
SciSeek -
SemiSeek -Semi-Conductor Info.
Steelynx -Links to steelmaking and Steel-Related Tech.