(Note that you need Java3D and a Java plugin to execute Panopano as a web applet. It will take quite a long time to load, too -- a wait screen will be implemented later on.)
Just Drag-&-Drop with the panorama with your mouse to change the viewing angle. The scroll wheel can be used to zoom/dezoom.
Panopano is a 360° Panorama viewer (Java/Java3D), and can also be used as a view editor (extracting/importing a "normal" view). It can display equirectangular and cubic panoramas, and virtual tours (popup images / video transitions between panoramas...).
If you don't know what a 360°panorama is, here is an example:
(Note that it is low quality, because sourceforge do not allow 30+ Mb files.)
You can see a better quality copy of this image, with an integrated 3D viewer, at 360cities.net
You can build such panoramas with a simple point & shoot camera -- and some free time. See the Hugin project on SourceForge if you are interested.The sourceforge Panopano project (where you can download the programme).
Note about this page: yes, I know, this is not even worthy of being called a website... If you want to help, feel free to contact me!