In my opinion, there is no reason to have icons on your desktop with windows 7. There is plenty of room on the taskbar for your most frequently used icons, every other icon can easily be found by clicking on the start menu. My documents, my pictures, other partitions or hard drives etc.
Unless in a work environment that demands it.
I don`t think what you want to do ( double click the desktop to hide the desktop icons ) can be done with windows 7 natively. If I`m wrong, someone correct me.