Great selection of miscellaneous calculators – no acoustics, though

Great Windows 95/98/NT shareware calculator – all scientific functions, optional RPN notation

Dan Russel’s Page     
Acoustics and Vibration Animations     
Free Emulator of the classic HP41 calculator – neat

Mathtools – MATLAB files etc.     
The scientific portal for MATLAB files, toolboxes, links and resources

The MathWorks     
Developers of MATLAB technical computing software for engineering and science

Mathematical Equation Editor to be embedded into Mac and Windows based office software

Multimedia Physics Course
Very nice Physics tutorial with lots of cute animations

Windows 95/98 Mathematical Graphing Tools     
Large selection of freeware/shareware graphing tools