MOOCs (massive open online courses), many free, are a hot item. Using the links below, you can search by course, subject, professor, university.
iTunesU has 1000s of courses once you create an account (free)
700 free online courses from top universities
From computer science to anthropology and everything inbetween
Touted as nation’s largest provider; 33 University partners (Jan 2013)
Harvard & MIT not-for-profit’s approach – all free
Offering courses from outside academia
Free public health courses at the U
Most universities offering distance courses also offer fee-based distance learning for credit.
The U of M’s Digital Campus
Oxford’s courses (many have fees)
Cambridges’s courses (many have fees)