If your PC desktop is a little on the cluttered side then you'll probably find yourself regularly hiding, then revealing its icons. But while you can do this from Windows - right-click an empty part of the desktop, select View > Show Desktop Icons - it's not exactly convenient.
HideDesktopIcons offers a simpler solution. Just download and unzip the program, save it to a safe folder somewhere, then drag and drop it onto the Quick Launch toolbar, Start Menu or task bar (in Windows 7) to create a shortcut. Then click it to hide the desktop icons, click it again to reveal them: easy.
Maybe you'd prefer to use a hotkey? Right-click the program's shortcut, select Properties > Shortcut, and click in the Shortcut Key box. Think of and press an appropriate key combination that won't interfere with anything else - Ctrl+Alt+I, say - and it'll appear in the box. Click OK, and pressing your chosen key combination should toggle the desktop icons on and off all on its own. (No luck? Try placing the shortcut on the desktop, or the start menu, or try another hotkey.)