Has it been a while since you last bought a car, even a used one? Are financial realities causing you to consider giving up owning one at all? Welcome to the club. America's auto population is shrinking along with annual sales (which lost a whopping four million in 2009). The 16 million annual sales year is likely to be ancient history in the U.S. Did you notice that they're now selling more cars in China than in the auto capital of the world?

America's dean of environmentalists, Lester Brown, president of the Earth Policy Institute, said Wednesday that (just as U.S. oil peaked around 1970, and world oil is headed that way) we may have reached "peak cars." The U.S. had 246 million registered vehicles for just 209 million drivers -- that's saturation. But it was 250 million in 2008, and Brown thinks the shrinkage will continue -- with auto numbers possibly declining 10% by 2020.

"Shrinkage of nearly two percent in the car population is unprecedented," Brown said in a conference call. "The severe credit crunch and the highest unemployment of many years are among the more obvious reasons, but we're also seeing the market saturation that is also visible in other industrial countries. Japan reached saturation in 1990, and annual auto sales are down 21% since then." In other words, everybody that needs or even wants a car, has one.

Cities, especially in Europe, are also discouraging car use, and trying to get people to ride bicycles or take public transit. Overall, 90% of Americans have cars, but some cities are reversing the trend. More than half of New York City residents live car-free, for instance, and Brown said that only 63% of Washingtonians are car owners. In Copenhagen, Denmark, 30 to 40% of commuters ride bikes to work.