A large fraction of my time these days is spent viewing online courses. Coursera (featuring courses from Stanford, Berkeley, Michigan, Penn and Princeton) and edX (featuring MIT & Harvard) are spearheading free online access to high-quality top university courses. Udacity, founded by former Stanford professor Sebastien Thrun, is also noteworthy, though the content is not as valuable as the other two. I’ve taken all but one of the Coursera classes. These courses have mostly been computer-science related, though the variety of the subjects taught will soon expand to the humanities and other subjects. For me, the most beneficial part is...