Lock Your Desktop Icon - If you want to be able to quickly lock your desktop with the swing of your mouse, do the following.
Right click on your desktop, and select "New", then "shortcut". Paste the following command in the location that pops up: %windir%\System32\rundll32.exe user32.dll, LockWorkStation
Click Next, type in "Lock Desktop" for the name, and click finish. You can move this icon anywhere on your desktop, including the quick launch bar, the task bar, or even leave it on your desktop.