Want to compare the various MOOCs (Massive Open Online Course) out there? The Chronicle of Higher Education has a handy guide here.
The formats are as varied as the people who tune in. Some consist mainly of lectures recorded on iTunes, while other courses seek to replicate a classroom experience by offering study groups, computer-graded tests, and weekly assignments. And while you might get a badge or certificate showing you mastered the material, you generally won’t get direct interaction with the professor, who may have recorded the lectures a few years ago.
If it is really true that the lectures are the least part of learning, some of these really do provide serious competition for traditional course offerings at second-tier institutions.