Winglet Picture

I was able to get a great picture at the airport today that illustrates two different winglet configurations in a single shot. In the foreground is an Airbus A319 (about a third the size of the plane in the background!). You will note it's winglets are not very large, but they extend both upwards and downwards from the tip of the wing. In the background is a Boeing 747-400. It's winglets are huge and extend upwards at an angle. I'm sure there are aeronautical engineers out there who can expound upon the benefits of the different configurations, but suffice it to say that they increase the efficiency of the wing, which translates directly to fuel savings and increased range for the plane.