1. A method of presenting a hierarchically-organized collection of objects with a computing device, the method comprising: displaying a first-level set of first-level objects in a prominent scale with the computing device; while displaying the first-level set of first-level objects in the prominent scale, displaying a plurality of second-level sets of second-level objects in a diminished scale with the computing device, each second-level set of second-level objects linked to a different first-level object and spatially positioned to a same side of the first-level object to which that second-level set of second-level objects is linked; recognizing selection of a chosen first-level object with the computing device; and responsive to recognizing selection of the chosen first-level object: zooming a second-level set of second-level objects linked to the chosen first-level object from the diminished scale to a prominent scale while shifting a spatial position of the second-level set of second-level objects in a direction towards the first-level set of first-level objects, wherein the second-level set of second-level objects are displayed in one or more intermediate scales between the diminished scale and the prominent scale while zooming; zooming the chosen first-level object from the prominent scale to an enlarged scale while shifting a spatial position of the first-level object in the direction, wherein the first-level set of first-level objects are displayed in one or more intermediate scales between the prominent scale and the enlarged scale while zooming; and while displaying the second-level set of second-level objects in the prominent scale and a portion of the chosen first-level object in the enlarged scale, displaying one or more third-level sets of third-level objects in a diminished scale with the computing device, each third-level set of third-level objects linked to a different one of the second-level objects.