The jaws of more than one vacuum truck driver, not to mention just about anyone else who depends on diesel-powered equipment and trucks to make a living, have dropped in disbelief as fuel prices zoomed sharply and steadily upward the past year.From July 2007 to July 2008, the national average price of a gallon of diesel fuel in the United States soared 65 percent, from $2.89 to a record $4.76 before dropping by a nickel a week or so later.Even the traditional price advantage that diesel users once enjoyed over gasoline buyers has been turned on its head. During mid-summer
