The site is too busy to add a comment right now but it's worth considering another option - "adding value" rather than jumping directly to podcasting the entire lecture. I agree that it is the author's (professor's) IP. Another approach is that they are expected to listen to the lecture and class is primarily follow-up discussion by STUDENTS demonstrating that they have learned the material. Moving students from passive to active, however, is still problematic for more than a few students. Read the entire post here.