(we have ferrets, so we are biased)..
Someone asked for a list of educational podcasts to deal with a one hour commute.
A few universities are putting lectures online for the general public ... Berkeley and Stanford are notable (the title comes from an animal behavior course) ... others offer individual courses - like an introduction to Kant's Epistemology. Physics geeks should check out the KITP blackboard lunch series (although I recommend the video version to see the blackboard for equations and diagrams) and CERN talks are useful
Unfortunately most courses and lectures are available only to local university communities, but there are signs this may be changing.