Apple’s New OS Could Save $10 million Annually in Energy: “Apple computer users who upgrade to the Snow Leopard operating system can expect to save about 10 percent in electricity a year.
Considering Apple’s annual sales of about 10 million computers, the savings will translate to more than 80 million kWh a year, or nearly $10 million in electricity, calculated against a power systems review of [...]“

(Via Environmental Leader.)