PresenterMate is a great tool to make your Mac desktop look clear and unobstructed during presentations, demos and screen-casts, and even to just clear the desktop so you could clear your mind.
When you open the application, PresenterMate puts an icon in the right side of your menu bar, and all the icons of folders, files, pages, pictures and anything else that might have cluttered your desktop, it all disappears from view. Close the application by clicking a button in the menu bar and all the icons come back.
When you open/close this application, it will momentarily relaunch your Finder, so just make sure you are not copying any files while opening/closing PresenterMate and you are good to go.
Unclutter your desktop, clear your mind.