Keep a second password protected screen. Fast switch out.

Say you are at your computer doing something private and someone comes in... Private Desktop will allow you to escape to your "public" desktop with the push of a button. Private Desktop allows you to keep a second password protected desktop containing all your private applications. Access to this desktop can be completely customized: its toolbar icon can be made either very small or invisible, hotkeys can be specified to remove you from the second desktop in a split second, and special key. List of files and programs to lock.