From the kind people at Duke:
For those interested in following CF Education Day this Saturday via the web, we use a free (advertising-funded) website that is not affiliated with Duke to carry the broadcast. The web link is http://www.justin.tv/dukecfcenter and it will be live on Saturday when the speakers are presenting. There is also a text chat window where people at home can type questions. One of our CF center staff will be monitoring the chat and can read the questions aloud when the presenters take questions.
Users at home do not need an account log in to Justin.tv. The chat is open to "anonymous" users, and they will appear as "justintv42738965" or some combination of numbers. This is beneficial in protecting our patients' privacy, but the risk is that sometimes random users (not affiliated with our CF center) will drop by and post in our chat area.
With that in mind, and knowing that we can't control what ads are presented by the service, I do recommend parental guidance if families are watching at home. I would hate for a child to see something that their parents would not want them to view (violent video game ad or similar). It is possible to view the video in fullscreen mode and this may limit the intrusiveness of advertisements.