If you use a Google hangout on air with a laptop that is pointing at the presenter, I don't see much extra cost, except perhaps the cost of the bandwidth(free?).

You probably even put a link on the dlang website that opens the hangout, with a different hangout for each session. If you are wanting to delay access to the videos you would have to go onto your youtube channel and make the videos private after the live streaming.

On Fri, May 9, 2014 at 9:48 PM, Andrei Alexandrescu via Digitalmars-d-announce <digitalmars-d-announce@puremagic.com> wrote:

Hi folks,

We at Facebook are very excited about the upcoming DConf 2014. In fact, so excited we're considering livestreaming the event for the benefit of the many of us who can't make it to Menlo Park, CA. Livestreaming entails additional costs so we're trying to assess the size of the online audience. Please follow up here and on twitter: https://twitter.com/D_Programming/status/464854296001933312

Thanks,

Andrei