I just listened to a BST podcast, and the interviewed talked about an ADX that plots the min value of ADX from N bars ago instead of the actual value and he said it was one of the best to determine early reversals. Not too sure about it, but I programmed it, from a smoothed ADX by Ehlers
(only the main trend indicator is computed using barsBack, not DI+DI-)
enjoy
Jeff
link to interview :


EDIT : optimized the indi a bit