Just a quick tip today — it is 92 in my office and 103 outside — the hottest day in recorded Seattle history. (I realize that this is nothing for some of you!)
My folders are arranged in a hierarchy — Pictures\year\shoot, with ocassional subfolders within a shoot. By default the Lightroom folder panel shows an image count for the parent folder, plus all subfolders within it. And if you click on the folder you see all of the images in that folder and its subfolders. In the snapshot below, I have a total of 1866 images from 2008. Most live in shoot subfolders (only a partial list is shown.)
If I click on the 2008 folder, I see all 1866 images, regardless of what subfolder they live in.
This is usually exactly what I want, but occasionally I want to see just images that live in the parent folder, and NOT in the subfolder. In this case I want to see just images that live in 2008, and are not in a subfolder. To do this, I go to File>Library Filters and uncheck Include Photos from Subfolders. Now what is displayed is just what lives in that specific folder:
So I have one image in 2008 that I forgot to file in a subfolder. When I click on 2008, I will see just that one image, and can move it to its proper subfolder.