by Rana Foroohar, Newsweek, USA - This spring, America hit a historic point. With average gas prices per gallon edging toward $4, America's notoriously profligate ways started to change fast. Americans are driving less, using mass transit more, buying fewer gas guzzlers, indeed shopping less wantonly in general, and lowering their previously unshakable confidence as consumers. Suddenly, Americans are acting differently; if not exactly like Swedes, then not quite like themselves, either. It's a shift that could change the world.