The Saudis have finally begun to worry that runaway oil prices are not in their long-term interest. For them the best of all possible worlds is one in which oil costs enough to ensure them a steady flow of huge profits but not so much that consumers switch to alternatives. But in the six months that ended April 30, Americans drove 30 billion fewer miles than in the same period during 2006-07, according to the Transportation Department. Toyota's first hydrogen-powered car just rolled off an assembly line in Japan. If this keeps up, the world will no longer be addicted to oil.