http://en.wikipedia.org/wiki/Videoconferencing
http://www.webopedia.com/TERM/V/videoconferencing.html
http://www.smashingapps.com/2010/08/05/top-12-sites-for-online-video-chatting.html
http://www.eyenetwork.com/_assets/documents/EyeNetwork_VC_Advice_for_candidates.pdf