Tony Hirst embeds the real-time twitter backchannel discussion into the JISC10 conference keynotes (or if you prefer your video without subtitles http://www.jisc.ac.uk/events/2010/04/jisc10/keynotes.aspx). Something for WCeLfest2011?
On dotSUB you can view, upload, transcribe, and translate any video into and from any language. A great resource for translations and also just same language subtitles.