I've just finished reading Greg Morris' Complete Guide to Market Breadth Indicators. A great read, I plan on adding some of this to my daily routine. Some of the stuff is easier to see relationships with than others, my guess is I'll skip the one in a blue moon indicators and stick with broad trend stuff that does not swing around much. Assessment of market breadth notably important.
The McClellan family of indicators gets a lot of mention there and I have seen them elsewhere. I've not seen all of these as an option on sites I've used before so I went to their site: http://www.mcoscillator.com/
It looks like too much information to me. In particular I note them calling for bullish moves in June 08 and Oct 08 that clearly did not materialize.
I wise man once wrote to me that "Only price pays".