I did not like the predefined categories of pictures that the OS installed for desktop pictures. So I organized them myself, but the Desktop preferences panel did not reflect the changes. This bugged me to no end.
After some browsing around, I found the file I need to modify to have the pop-up list in the panel reflect the folder names I wanted to use. The file is located in the following directory:
/System -> Library -> PreferencePanes -> DesktopPictures.prefPane -> Contents -> Resources. The name of the file to edit is Collections.plist.
You can open and look at the file but in order to make and save changes I would suggest to be root to make the changes. In that file, I deleted all the groups except for two of them. What I mean by a group is, for example, the following:
{
identifier = "Stock";
path = "/Library/Desktop Pictures/Stock";
showScalingPopUp = NO;
}The quotes for the identifier were added by me since one of my indentifiers has a space in it, this was the way i got it to display the names in the menu with the spaces. If the identifier is only a single word you do not need the quotes but I did it for consistency. You can change the path to whatever you want to have for the location of the images as far as I can tell. I hope that this works for others like it did for me.
Mac OS X Hints
http://hints.macworld.com/article.php?story=20020304092103920