I have never really experienced writer's block. I always seem to be filled with ideas that drive me to the computer. I've got friends who have spent ten years on a single novel. Spending that much time on one book probably would drive me to do anything to keep from sitting down once again to work on the thing. I generally write a book in about a year. And often the day I finish (of course books are never really finished. Tinkering goes on forever, even after publication), I start the next one.