SI-Convert Lite provides an easy way to find and convert any unit.
It includes thousands of conversion factors grouped into 36 categories.
SI-Convert Lite also converts algebraic functions (e.g. (1*58/(2-6)+10^-2.5 ) grams to pounds), converts letters and numbers into ASCII and binary values, and includes the most commonly used physical constants.
Other features include copy/paste functions, search, the ability to invert your values, a calculator, System Tray support, and more.
Limitations in downloadable version:
SI-Convert Lite is free. An enhanced version, SI-Convert Pro, lets you add and manage your own units.