Its basic function is to blank the screen with a hotkey (Pause key). You can restore the screen with the same hot key.
You can use this as a manual screen saver, where you choose when you want to clear the screen.
AS-Blanker is portable and has no interface. Just run it and use Pause key to blank or restore the screen.
It works with Windows 2000, XP, Vista, and Windows 7. You can download (180kb) it free at source.