I've been working on a UI control with some similarities to these, but built specifically for skimming long lists. The general idea is that the faster you scroll, the more "zoomed out" the view becomes. As the scrolling speed slows, the zoom returns to normal. So if you're scrolling quickly through a very long list, it's like flying at a higher altitude. The list includes big "landmarks" (e.g. letters of the alphabet) to provide a sense of position. The control is tuned so that the apparent velocity of a given item through the control's "viewport" remains within the same narrow range. Instead of getting an illegible blur of items zooming past, you instead see an increasingly zoomed out view as scrolling speed increases. In an environment that provides momentum scrolling, the overall effect is like taking big, high leaps along the list in low gravity.
