[font=Verdana]I have a mouse with two thumb buttons (a Microsoft Wireless Intellimouse Explorer) and its software (Intellipoint) lets me set specific functions for any software. I set the rear thumb button (closest to the base of the thumb) to Undo, and the front one (closer to the tip) to Redo. This lets me work extremely fast and experiment freely without having to worry about screwing something up. I have messiah set to Auto Key Create, so having such a quick and easy Undo is wonderful. Try it!