I just saw something today that's amazing, brilliant, cool, and obvious in retrospect (it could have been in the net-pbm tools 10+ years ago, if anyone had thought of it), that is currently research demo, but I predict that in a couple of years, it will be an unremarkable and standard part of the user interface, and UIs that don't have it will seem stupid and clunky.
It's called Seam Carving for Content Aware Image Resizing, and it's a way to resize and rescale images in a way that's useful, fast, headslappingly obvious in retrospect.
