Adama D. Brown writing over at Brighthand reviews HP's iPAQ rx5915 pocket PC which combines a GPS navigation system with a multimedia player and internet access. 'The rx5915 is the first iPAQ designed specifically for a landscape orientation. By default, the system starts up with the directional pad on the right hand side of the screen. If you don't like this orientation, however, among the application buttons along that edge of the case is a button to rotate the screen. Pressing it once switches you to a portrait orientation with the directional pad below the screen and the buttons on the bottom. Keep pressing it, and you'll rotate through all four possible screen orientations, including 180 and 270 degree rotation.
Read: HP iPAQ rx5915 Review - Brighthand