I ran across a reference to Stephen King and how dreams relate to his writing, specifically the novel, Misery (this is from an interview he did with UK journalist Stan Nicholls):
"Like the ideas for some of my other novels, that came to me in a dream. In fact, it happened when I was on Concorde, flying over here to Brown's. I fell asleep on the plane and dreamed about a woman who held a writer prisoner and killed him, skinned him, fed the remains to her pig, and bound his novel in human skin. His skin, the writer's skin. I said to myself, 'I have to write this story.' Of course the plot changed quite a bit in the telling."
This reference was part of a collection of ways that dreams have led to scientific and other breakthroughs, as gathered on the website of a supplement called Brilliant Dreams. It claims that you can improve your chances of lucid dreaming by taking the supplement, which is based on a substance called galanthamine, which is being investigated as a possible treatment for Alzheimer's. I have no idea whether it works--but it's expensive and seems not to be available in the UK.
A cheaper way to take advantage of your dreams is just to keep a pad and pen at your bedside and every morning jot down anything you remember. Over time, you'll find you remember more and more. Who knows, maybe the next Misery is waiting somewhere in your dreams...