A story in The New York Times last week reports the increasing popularity in Brazil of flex fuel vehicles that can use gasoline or ethanol interchangeably. Drivers with these snazzy cars can choose a fuel for the day's driving based on availability, price, or sheer whim. These flex fuel vehicles might have a market well beyond Brazil now that oil has hit $54 a barrel. While using ethanol as a transportation fuel won't solve all air quality problems, it can be part of the solution in many countries.