Highlight Investments provide java charts of the major US indices (
www.marketvolume.com ) showing normalised intraday volume - i.e. correcting for the skewed volume levels at the start & end of each trading day. I`ve been a subscriber for a couple of years and find it useful , in conjunction with TA, for spotting likely turning points.
I`ve been trying out their QQQ/SPDR/Dow pre-close trading signals since Jan`04, but so far the jury is out on their effectiveness. They aim to signal trades after substantial supportive/resistive volume spikes have accumulated against the current trend, indicating a likely trend change. The past performance figures (which don`t assume the use of margin) look good, although the older ones are, I believe, the result of backtesting rather than realtime signals.