Researchers at the Palo Alto Research Center have developed a new software program called Halo that makes it easier to view a map on the small screen of a PDA or a phone:
As a person navigates a map on a handheld computer, the software causes arcs representing selected offscreen locations to appear on the edge of the screen, as if the locations were surrounded by circles large enough that a portion of the arc just reached onto the screen. The user can sense how far away an offscreen location is by the curve and translucence of its arc, which indicates the size of the full circle and thus the distance to its center.
