How much do you enjoy that bubbling aquarium, swaying palm tree, or space flight while your computer is idle?  Enough to be paying for it?  The use of screen savers actually uses more energy than if the computer is just sitting idle.  If you let your screen saver run overnight, it could be costing you over $100 a year.  If you don't like having to re-boot your computer each time you use it, consider using the sleep mode.  That's the most energy-efficient mode and comparable to turning your monitor off completely, which is another

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money saving option.