David Case:

"Zipcar is a new service that enables you to rent a car by the hour. For most residents in Washington, Boston and New York, the company claims that it has a car available within a five minute walk. They're coming to other big cities soon. But don't think of Zipcar as a rental agency. [...] Here's what you lose: auto loan and insurance payments; trips to the service station to get the car fixed; idling in line at the motor vehicles inspection service. If circling your neighborhood for half an hour in search of a parking spot is a regular chore, you can forget that, too."

I'd gladly use this service instead of buying or leasing a car. But there's no such thing here in France (most people buy their cars and the average vehicle is 8-year old). I'm about to get rid of my Golf and will replace it with an Alfa Sportwagon at the end of the month. My American readers might want to look at these pictures, since I don't think the Alfa 156 range is sold in the US, and the "sport station wagon" concept might seem weird too. Well, huge gaz-guzzling SUVs seem strange this side of the pond. Alfa (an Italian brand) has a good image with car lovers here, and they apparently improved reliability a lot.