This will label me a geek... but I think the best example of what you're talking about is shown in the anime movie Macross Plus where they have an airplane that changes the configuration of it's wing thru nanotechnology, sweep, chord and geometry are all infinitely adjustable by the pilot. This may one day be a possibility, but for now there is not much you can do to gain this ability without sacrificing weight or huge amounts of money.
You must always design a wing to be best at what it's role will be, and the tradeoffs you get from such extreme wings can significanly affect the handling of the airplane in all other flight envelopes. Two examples:
The U-2, a wing that gives so much lift that the airplane can't land unless it's fully stalled.
The F-104, a wing made so fully dedicated to speed that blown flaps were needed to get landing speed slow enough to make landing at all possible. The F-104 killed a great many pilots because of this wing.
So yes, a variable geometry wing can be made, but the cost will always outweigh the benefits.
I know there have also been some tests with the RQ-7 Shadow UAV. The wing houses fuel bladers that define the max size of the wing.
When the plane takes off the plane has a thick airfoil cross section, but as fuel is consumed the foil thins out as the bladders empty. The wing surface settles down onto a frame defining the minimum thickness profile.
This alows the plane to carry more fuel than a thin wing section would alow, and provides added speed and efficiency as the reservoir empties. It also seems like it is not to costly to impliment, although the wing shape is not constantly varied to increase performance as some of the things mentioned above.
