Open Culture  offers an impressive list of over 500 free online college courses, in the liberal arts and sciences. Many are offered via YouTube or iTunes, in either audio or video format. A few are web-based. But wow, what a list.–Bob Rankin.     Check out courses in Achitecture (from MIT), Art (from Oxford University), Philosophy (from Notre Dame), History (from Yale), Economics (from UC Berkeley), Film (from UCLA), Geopolitics (from Stanford), Law (Yale/MIT), Literature (Harvard), Music, Philosophy, Religion, and Sociology. In the Sciences field, you can find hundreds of classes in Aeronautics, Astronomy, Biology, Chemistry, Computer Science, Engineering, Mathematics, Physics and many more. If you want to learn a new language, check out Open Culture’s free language lessons for Arabic, Chinese, French, German, Italian, Russian or Spanish.