Calculators

Animal Gestation Calculator
Utility providing gestation information and the estimated birthing date for a large list of animals.
http://www.formatinternational.com/software/gestate_palm.htm

Creative Creek software
Makers of "MathU" and "One Plus One" financial and scientific calculator software.
http://www.creativecreek.com

RPN
Programmable, postfix scientific calculator.
http://www.nthlab.com/software/rpn/index.html