It would be so surprised for me that very few people ever knew about iTunes U. Come on, what’s wrong here? It is a great place for you to study through Harvard, Yale, MIT, Stanford and Carnegie Mellon. And all courses are free. Many people dream about these universities, so I think it is worth my efforts giving an advertisement and some introduction.
1/ Open iTunes and choose iTunesU
2/ Select the university you want to learn
3/ iTunesU has a lot of cool universities: Harvard, MIT, Stanford, CMU
4/ Courses at Yale
5/ Download the video you like