sorry but many of you are talking ass.
as someone who's taught college-- i wouldn't let some random person from the street to sit in my class.
you're not registered? fuck off.
really. who would want the aggravation?
now there may be some large lectures that you can attend, but not a small classroom.
just the other day a friend of mine with an MA *registered* for a graduate class in her field and she was asked to leave unless she's admitted to the doctoral program. oh yes.
anyway on the subject of large lectures, which are more or less public, berkeley has been putting their shit on youtube.
http://www.youtube.com/user/ucberkeley
it's mostly science though.
kentucky might have something. not sure what.