1. An interactive, electronic method of authoring annotated traversals through visual data, the method comprising: displaying the visual data, wherein the visual data; interactively defining a traversal of the displayed visual data by positioning a resizable overlay window relative to the displayed visual data, wherein said resizable overlay window is resizable while the visual data is being displayed, said traversal comprising a subset of motion video that specifies a time-based sequence of frames of said motion video, each of said frames comprising the visual data delineated by the overlay window, wherein the displaying said visual data comprises displaying the visual data in a cylindrical layout, and wherein said positioning of the overlay window is defined by a field of view of a virtual camera located centrally to said cylindrical layout; annotating the traversal; and storing a persistent record of the annotated traversal.