I came across the idea that it might be interesting not to just divide the indicators into 24 hours but also break it down into each day of the week since there are diffrences too. (usually wednesday is the day with the most volatility as far as I remember).
After re-reading my papers with interesting approuches I came back to the Marney-Indicators. To have an idea about the indicators the article in Currency Traders is worthwhile to read (I guess a link is somewhere in a previous post)
Haven't checked entirely in detail but in Multicharts is the Marney Range Indicator and Marney Volume Indicator, both editable and according to the header written by Caspar Marney himself.
For myself I have an approuch using the cyclic changes of ATR with forex-pairs. Knowing these repeating waves is great to jump in before the market starts moving. With discretionary context checks the overall market direction needs to be checked though. The Marney Range / Volume indicators could be better in checking the start of the action and especially in case its different to the 'usual' volume / range.