The script worked pretty well in sky mode right away, with one problem - it showed all of the placemarks out there (restaurants, etc).
I did some research, and it seems that you cannot determine via a network link whether a person is in sky mode or earth mode. If any of you have information other than that, please let me know.
So, I created a new category for items called "Sky Mode". This is a special category, as the items in it are hidden even when "Show ALL" is selected. When browsing the earth, use any category (including "Show ALL") and you'll see only earth-related items. If you switch to Sky Mode, simply choose the "Sky Mode" category from the KML package and you'll see those items instead.
Also, if you create a new thread up there, you must choose the "Sky Mode" category for it for it to work properly.
I hope that is clear enough. If you have any suggestions for improvement, please let me know.