1. A method of navigating between application contexts in a portable device, comprising: displaying a current application context of an application in an application display region of a display; displaying a navigation bar adjacent to the application display region, the navigation bar including at least three horizontally adjacent regions, comprising a current context region for displaying an indicator of a second application context comprising the current application context, a prior context region for displaying an indicator of a first application context comprising an application context preceding the second application context, and a link region for displaying an indicator of a third application context; upon detecting user selection of the prior context region, shifting operation of the portable device to the first application context, including displaying in the prior context region of the navigation bar a fourth application context comprising an application context of the application, if any, that preceded the first application context; and upon detecting user selection of the link region, shifting operation of the portable device to the third application context, including displaying in the prior context region of the navigation bar an indicator of the second application context.