This story at Nautilus goes into some detail about the memory techniques a man used to memorize John Milton's epic poem of the fall of humanity, Paradise Lost. It's a discussion of some method called "deep encoding," which I'm afraid I didn't quite grasp. Maybe I'll read it again some day before 9 PM.
What struck me as cool is that the guy now can "read" Paradise Lost any time he wants even without a copy in front of him. It's all in his head.
You'd need never again fear forgetting to take a book on the plane.