PTViewer 2.8 Beta 8 is a Java Applet for Spherical and Cylinder Panoramas. Please look here: PTViewer for more Information.
Controls: Click in the Panorama and drag the mouse to change view. Press + or - keys to zoom in and out. You can also press O and o to give the panorama display an offset for horizon positioning, a tool for panoramas of which the horizon is not in the middle of the panorama.
(pretty useless for the panos displayed here, but just for fun...)