Thanks again... one more question though. I followed your idea of putting a repeater in the master page. Then I used the "Menu item image" field to set an image to override the default on any page. It works perfectly except I can't figure out a way to make it inherit the image from beyond just the parent. Here is what I did in the transformation:
<img alt="" src="<%# IfEmpty(CurrentDocument.DocumentMenuItemImage, IfEmpty(CurrentDocument.Parent.DocumentMenuItemImage, "/media/images/page-banner.jpg", CurrentDocument.Parent.DocumentMenuItemImage), CurrentDocument.DocumentMenuItemImage) %>?width=960&height=136" >
Like I said, this works for a parent and child but not when there are three or four levels. I was not sure what you meant about using inheritance in your last reply because that is what I was trying to do originally with the editable image in the master page... and as we have discussed, that does not work. Maybe I am just not understanding your suggestion fully.