Hypermiling a Transatlantic Boeing 777

It was an arranged test where the pilots had more flexibility with their route to optimize their use of prevailing wind, and they saved over 1,400 gallons of jet fuel. There are 600 transatlantic flights daily. It would take some overhaul of the international air traffic control system, but with the advent of GPS navigation rather than ground/radar, this is possible.

One thing they don't mention is if it significantly increased flight time.

http://www.wired.com/autopia/2010/06/united-airlines-tries-hypermiling-with-a-boeing-777/