New MacBook owners are reporting that Leopard's System Preferences pane includes a small change. While many would have been ignorant to this almost-invisible tweak, some users have discovered that the Energy Saver icon has changed from the old incandescent bulb to an energy-efficient fluorescent bulb.

The move was undoubtedly made to reflect Apple's latest environmental efforts with the new MacBook line. The new MacBook and 15-inch MacBook Pro both have a precision unibody enclosure crafted from a single block of aluminum, resulting in a thinner, but also a greener laptop. It meets the stringent low power requirements set by the EPA and the U.S. Department of Energy, giving it ENERGY STAR certification.

“Apple has invented a whole new way of building notebooks from a single block of aluminum. And, just as important, they are the industry’s greenest notebooks,” said Steve Jobs, Apple’s CEO, upon introducing the new devices on October 14. “The new MacBooks offer incredible features our users will love – like their stunning all-metal design, great 3D graphics and LED backlit displays – at prices up to $700 less than before.”

In fact, the entire new MacBook family meets stringent Energy Star 4.0, EPEAT Gold and RoHS environmental standards, and leads the industry in terms of the elimination of toxic chemicals by containing no brominated flame retardants, using only PVC-free internal cables and components, and energy efficient LED-backlit displays that are mercury-free and made with arsenic-free glass. The EU's 2006 Battery Directive, part of RoHS, updates existing regulation from 1991, and seeks to prevent the unnecessary use of toxic metals in batteries, but also imposes new device designs, making it easier for the user to dispose and replace his / her own battery. By allowing users to swap not just the battery in its new notebooks, but also the storage unit, Apple has addressed this directive as well.

Apple's new LED-backlit display found in new MacBooks is another environmental breakthrough. LED technology uses 30 percent less power than conventional LCD displays. The LED-backlit display is mercury-free, highly recyclable, and encased in arsenic-free glass. And, because MacBook is environmentally innovative, it has earned the highest rating of EPEAT Gold.

Did you notice the change prior to reading this article? Do you think there are more changes like this to discover?