Unclutter lives hidden on your Mac until you need it, and then drops down from your menu bar with a quick flick of the mouse to show you your clipboard, a holding pen for your files, and a place to jot notes. This pane scrolls back up when you don't need it, and you can even take each of the individual cards and let them hover over your screen while you work. The concept is that you use this for your temporary storage instead of your Desktop, keeping things over there clean. It also works great with full-screen mode, too, meaning it's now quickly earned a permanent home on my 11" MacBook Air.
Check It Out: Unclutter Cleans Up Your Desktop and More