Spring or Winter 2011 semister is just started, so are the online videos from major universities. These are complete video courses i.e all the lectures are made available by the time course is over. Some universities make the lectures available on the same or the next day of the class. You can subscribe to the courses by mail or feed and learn along with them. Both the video and audio of the lectures are available for free download.
Has 30 video and close to 50 audio courses. You can download all the lectures. Check out here.
Has 18 video and more than 70 audio courses. All theses courses can also be accessed through iTunes as well.
Mostly about chemisty related subjects. Has close to 20 courses. Find all here.
If you know any other courses, please add them in the comment section.