If you think that Privacy is very important for you then you should definitely take a look at Magic Boss Key. Magic Boss Key allows you to hide the currently active window using a hot key. So if you want to hide a window or a browser suddenly when someone is coming behind then you can use Magic Boss Key to do that. The application is very small and absolutely free. The user interface is very good. I feel this is the software that everyone should install.
Feature highlights include:
You can instantly hide windows with a secret key combination.
Easily restore all applications exactly to the same state.
It is extremely fast with low system resources consumption.
You can Cover task bar and desktop icons.
Includes support for multiple languages like Arabic, Hungarian, Korean, Polish and Spanish.
Windows Vista/2003/XP/2000/Me/98 compatible.