I'm a huge fan of Michael Wesch and what he (and his students) are doing with the Digital Ethnography program at Kansas State University. If you haven't already seen his most brilliant videos Web 2.0 ... The Machine is Us/ing and A Vision of Students Today you really do owe it to yourself to check them out.
Wesch gave a great presentation at the Library of Congress on June 23rd, 2008. Wesch is way more than a Cultural Anthropologist and teacher. He understands what these new digital media channels are better than most Marketers and - more importantly - he presents these new shifts in media in a clear, fun and interesting way.
Here's his fifty-five minute presentation - An Anthropological Introduction To YouTube. Take the time to check it out...