For video (and audio) streams from the yearly CCC Congress in Berlin see http://28c3.fem-net.de.
The schedule can be found at https://events.ccc.de/congress/2011/Fahrplan/.
Within the next days or weeks all the talks should be downloadable from ftp://ccc.de/congress/2011/.
The streams were very good, and the talks doubly so. I'm looking forward to watching the talks we missed, too.