An imporant healthy habit, as discussed in the Longevity Project, is lifelong learning. Today there are several opportunities to pick up new skills and learn new subjects online. Over the past year, Jeremy and I have found several resources to learn and actually receive a completion certificate from top universities for free. Subjects include (but are not limited to) business, finance, nutrition, the sciences, engineering, programming, history, math and philosophy.
Check out the links below and see if there may be something worth your time.
MIT Open Courseware: http://ocw.mit.edu/index.htm