Good question, Bill.
I can't think of any site off the top of my head (although I know I've seen plenty), but the key to setting this up (outside of hiring a custom designer) is to find a theme that has homepage widgets that allows you to create a more custom homepage.
Also, many premium themes give you the option of removing the sidebars altogether if you want.
One theme I'd love to try and haven't yet is Headway. It allows you to more or less draw out your theme design but I don't know how completely customizable it is. From what I heard it gives you more design control in a WYSIWYG format.