The Show Desktop icon is probably one of the most useful features of Windows since it allows you to quickly access the desktop even if you have 20 programs open. If your icon is missing or you deleted it, you can quickly recreate it. Open Notepad and type in the following:

[Shell]
Command=2
IconFile=explorer.exe,3
[Taskbar]
Command=ToggleDesktop

Now just save the file as Show Desktop.scf and drag it to your Quick Launch bar. Done!

Don’t want to do the work yourself? You can also download pre-created ones for Windows XP or Windows Vista.