It would be really nice if gv (or any other PS viewer, may be ggv?) could show PS files in full screen presentation mode. By "full screen" I mean the thing that screensavers do - when everything disappears (including "stay on top" windows and toolbars) and it uses the whole screen to display the PS - no menus, no window borders, just the file itself.
Unless you have a patch, this is not something we're likely to take the time to add. Perhaps try to get the gv authors to add this? (or, as you mentioned, check with ggv.)