1. A system for displaying images of a virtual three-dimensional book having one or more virtual pages, the system comprising: a display system capable of executing a display program, wherein images of the virtual three-dimensional book are produced on the display system, a page selection function is provided, the page selection function comprising a user-selectable scale along an axis of the virtual three-dimensional book for selecting virtual pages, the user selectable scale being non-linear and a function of a degree of interest value, and the degree of interest (DOI) value comprises a page distance from a currently displayed page, falls off exponentially from the currently displayed page, and is determined for each page number p using the function DOI ⁡ ( p ) = 1 A ⁢ ⁢ ⅇ k ⁢  c - p  wherein A and k are constants, e is the base of natural logarithms, and |c-p| is the absolute value of the difference between a current page number c and each page number p.