T. Alan Keahey, Los Alamos National Laboratory
http://www.cs.indiana.edu/hyplan/tkeahey/research/papers/infovis.98.html
(per Keahy:) This paper describes a general formulation of the "detail-in-context" problem, which is a central issue of fundamental importance to a wide variety of nonlinear magnification systems (a.k.a. fisheye views, distortion presentation). The basic characteristics of nonlinear magnification are non-occluding in-place magnification which preserves a view of the global context.
This technique has received a wide range of attention. However, it was mentioned at the conference that it may not seem to be effective for very large data sets. It allows magnifications up to about 5x and the distortions can be very disconcerting to the viewer during navigation. Note that Keahey has created the Nonlinear Magnification Home Page http://www.cs.indiana.edu/hyplan/tkeahey/research/nlm which provides a wealth of information including an excellent bibliography.on the technique.