I'm not sure if you need to be a premium member to view this. it is a webinar by the guy that wrote that noise indicator I talked about before. He talks a lot about opening ranges, ACD, noise levels, pivots, and other measurements of volatility. I haven't had a chance to watch the whole thing yet but for a guy like me that is pretty new to studying the markets from this angle it is pretty informative.
http://www.bigmiketrading.com/webinars/jul31_2011/fat_tails_session_indicators/
http://www.bigmiketrading.com/webinars/jul31_2011/fat_tails_session_indicators/