Personally, I set the heading bug to the runway heading as soon as I know what runway I'll be blasting off from. When assigned a departure heading, I spin the course selector to that heading. I also fly with guys who put the departure heading and left or right turn in the scratchpad on the FMS. If I'm flying with someone like that I do both. I would venture to say that taking off on the wrong runway is a greater hazard than forgetting the departure heading and having to ask tower for it again.