"The Associated Press reports that the major US carriers, desperate for any idea that will conserve fuel, are cutting flying speeds on some routes.
Jetblue claims that extending each of its flight by two minutes saved $13.6 million last year. Southwest Airlines, despite a fuel hedging program in place that leaves it in better shape than most of its competitors, will save $2 million a year by adding one to three minutes to each of its flights."
http://blog.wired.com/cars/2008/05/to-cut-fuel-cos.html