I used to walk everywhere. Great for keeping you fit, bad for giving you thighs like treetrunks that won't fit in skinny jeans. Nowadays, mostly buses. Trains for longer distances.
My parents can drive, but neither has a car, the majority (though not a large majority) of people I know in Oxford are the same. With petrol prices at roughly ten dollars a gallon, car tax, road tax etc, I don't know many people who can afford to run a car.