Thanks George. I should have updated this post a while ago. I found that with Win7 there is now a little button at the far right of the task bar for this function. If you mouse over it, it will ďPeekĒ or temporarily show the desktop. If you click on it, the closes any open windows and shows the desktop.
I used to have to create a shortcut for this and place it on the taskbar, but it looks like MS must have caught on to this with Win7.