I had already a quote for this week, so the following will be the quote for the weekend:
Kevin Murphy holds comparative advantage in all forms of production.
Read all 10 top facts about Kevin Murphy :-).
Via Greg Mankiw, again.
PS. And if you have some more time, (re)visit one recent empirical test of the well known three-type labor market theoretical framework, which can be summarized as: there are only three types of labor: unskilled, skilled and Kevin Murphy :-).