Other scientific calculators
Google scientific calculator
is amazing. In fact, it is much
than a calculator.
is probably the best on-line calculator for matrix operations out there.
has a very nice unit converter.
The Wolfram Alpha can also be used as a
Fundamental Physical Constants
are provided online by the National Institute of Standards and Technology.
The "FUNDAMENTALS OF ENGINEERING SUPPLIED-REFERENCE HANDBOOK" is probably the best free engineering handbook on the web. You can get it from the
(where they ask you to register) or from
(where they don't).