Not sure if this is exactly news, but it's a big help for any other students in science classes out there or anyone else who needs to occasionally convert picometers to fathoms. In the terminal, just type units, which is a UNIX app that knows how to convert between 501 different units of measurement, everything from inches to furlongs to stones.
[Editor's note: Type "man units" to get a couple of useful pages that explain how to use the program. Note that it will not do Fahrenheit/Celcius, but it looks like it can handle almost anything else!]
Mac OS X Hints
http://hints.macworld.com/article.php?story=20010531165747829