Converter let's you convert between different units.
These include: Area, Energy, Force, Length, Mass, Power, Pressure, Radiation, Temperature, Time, Velocity, and Volume.
There is a separate color conversion utility to convert between RGB and hex values, which is nice to have when working with web colors.
If you need to do some further calculating of your own, there's a calculator there too. To get to the calculator, click on the equal sign.
Mac OS X Public Beta