>>
>> Your task is to write a units converter script. The input to the
>> script must be three arguments: the quantity, the source units, and
>> the destination units. The first example above would be run like  
>> this:
>>
>>      $ ruby convert.rb 50 miles kilometers
>>
>> Or, using abbreviations:
>>
>>      $ ruby convert.rb 50 mi km
>>
>> Support as many units and categories of units (i.e. volume, length,
>> weight, etc.) as you can, along with appropriate abbreviations for
>> each unit.
>
> This will be interesting. I'm not going to endeavor into myself b/c I
> help maintain Stick (http://stick.rubyforge.org) which already does
> this (and there's another lib out there that does it too). But it will
> be interesting to see how others approach it.

Note to everyone else: using another lib, such as stick, is considered  
cheating for this quiz.  :D