Abstract: A navigation system provides multimedia annotations based upon the present location of the vehicle. These presentations may comprise advertising or text or other information entered by the user and associated with a specific location or locations. The navigation system also provides a removable media reader which obtains additional information based upon which the navigation system operates. This additional information may include multimedia annotations which are location-based. The navigation system further includes a wireless communication system which interacts with and provides further location-based multimedia annotations.

Abstract: An ascending and descending device, or ladder, having a single central mast and a hand and two foot supports axially slidably engaging the mast. Each hand and foot support has a spring biased clutch normally preventing axial motion of its associated support along the mast, and a lever for releasing the hand or foot support to move along the mast. The hand support has weight bearing platforms, or grips, projecting to both sides of the mast. Each foot support projects to one side of the mast. The foot supports are tethered together to limit the distance by which they become separated when lowering one foot support. The mast has at its bottom end a base having folding legs. The mast selectively receives at its top end a pronged support for engaging the roof of a building and a chair to enable a person to remain seated above the ground. The chair has a safety tie for securing the chair to a tree.