CNET News had an article last month about Stanford's iTunes initiative. Basically, Stanford has made audio (described as "Stanford-related digital audio content" on the website) available for download through the iTunes music store.
To access Stanford on iTunes, you must go to the program website and follow the link on the main page (or click here).
I get the impression from the article and the Stanford website that the service is primarily intended for alumni, even though anyone can download the files from iTunes. I find this a puzzling decision - is there truly a strong demand from alumni for university lectures? I would like to see Stanford make the page accessible from the main iTunes Music Store, giving everyone a chance to listen in.