Applications :: Can I Create Subfolders In IPhoto?

So I've generally avoided using iPhoto for my pictures, mostly due to the familiarity of the old school method, which is just putting different folders and the like in the "Pictures" section of finder. So, if you click on "Pictures," you'll see various categories: family, friends, celebrities, sports, wallpapers, etc. Then when you click on, say, family, you'll have other folders of the various family members of families. Then you click and you see the pictures, etc.

Is there a way to organize this in iPhoto in the same fashion? Where I can have various main categories (i.e., family pictures), but various subcategories (i.e., the Smith Family, the Doe family, etc.) within the folders? Or am I fine with how I have it now?