In the case of blank page "snow blindness" I feel it's best to just write anything—I mean ANYTHING. Let's face it, any first-words-on-paper are likely to be substantially edited, as it is. In the case of writer's block occuring in a work-in-progress, sometime's it is best to take a break—a walk, clean the kitchen, play guitar—anything to clear your mind. Other times, though, I just continue to bang my head against it until it comes. There is no easy way out.