My son had colic for the first six months. We love him like crazy but were driven to our wits end, crying all evening. He would scream for hours on end and not even breast feeding would console him. My husband and I dreaded the nights because we were up until 1 in the morning pacing with him.
The only thing that seems to help him sleep was bouncing on the exercise ball. It can get tiring but I get a good ab workout at the same time.