Walmart’s plan to develop an eco-rating for all the products it sells, including electronics items, is ambitious, “yet may translate into only to only a small step for sustainability,” according to a spokesperson for Consumers Union, the nonprofit publisher of Consumer Reports.

The Benton, Arkansas-based retailer’s Sustainable Product Index is expected to provide a snapshot view of each product’s environmental impact during its life cycle, from raw materials through disposal. As a first step in the five-year program, Walmart will assess the sustainability of its more than 100,000 suppliers worldwide. Each supplier will be asked to respond to a 15-question survey (PDF) that covers energy and climate; material efficiency; natural resources; and people and community.

Urvashi Rangan, Ph.D., CU's director of Technical Policy, says that "collecting detailed product information and translating it into a simple green rating is a complex task and, ultimately, only as accurate as the data and evaluation that goes into a life-cycle analysis.”

As we’ve covered before, there's already a multiplicity of approaches in the marketplace to so-called green ratings. 

For more on the Walmart initiative, see the post by our colleagues on the Home and Garden blog. We also have a host of other information available on the environmental dimensions of electronics gear.  

There’s lots of online buzz about Sony’s announcement yesterday of two Blu-ray megachangers that can hold 400 discs, including Blu-ray and DVD discs and audio CDs. The supercharged BDP-CX7000ES, which lists at a lofty $1,900, is already in stock at SonyStyle.com, while the more modestly featured BDP-CX960, $800, is set to arrive this fall. A high-end single-disc player, which includes features such as built-in Wi-Fi, is on the way for delivery in August at $700.

We’re putting the finishing touches on new Ratings of single-disc Blu-ray players, including the Sony BDP-S360, which lists at $250 in Sony’s Web store. Most of the models sell for $200 to $400, pricing that might make Blu-ray players more appealing to more buyers. Check back next week for full Ratings (available to subscribers) of this and a dozen or so other Blu-ray players. We'll be buying and testing the BDP-CX960 when it hits the market. — Eileen McCooey

In the same vein as its “Blue Label” series of consumer-conscious portable computers, electronics retailer Best Buy has grouped together a line of laptops with students in mind.

Best Buy has dubbed the line “Next Class", four laptops developed to be powerful, versatile, and compact enough to go from class to class, and have their batteries last the whole time too (typically 3-6 hours, according to Best Buy).

The quartet—Toshiba’s M500, HP’s DV4-1465DX, the Dell Studio Chassis, and Sony’s VGN-NW125J/T—offered exclusively by Best Buy—may be a bit underpowered for some. For instance, the Toshiba doesn’t have a Core 2 Duo processor, and the Dell has no optical drive—and still weighs as much as the others. But with prices ranging from $650 to $800, these laptops do appeal to the budget conscious student.

And all include, at no extra cost, a copy of Microsoft Office 2007 Student Edition—which typically retails for $150 (although we found it at Amazon for $86.49)— plus at least 12 months’ virus protection. And, if you buy one of these systems now with Windows Vista installed, you get a free upgrade to Windows 7, when it’s released on October 22.

If you are thinking of buying one of these computers, here are a couple of caveats: Make sure a model is right for you, check its specifications. And make sure the system fits your school’s requirements, which are usually posted on the IT department’s web page.

To see how reliable these laptop brands have been, or for reviews of comparable computers, see our Ratings (available to Subscribers). —Will Dilella

In a sign of the increased versatility of (and blurring of lines among) multimedia gadgets, the Consumer Reports engineers who test GPS navigators have just wrapped up their review of the XRoad G-Map—an application for the Apple iPhone.

The app is designed for the iPhone 3.0 platform and seeks to compete with standalone GPS units. Like Navigon, the navigation company which now focuses solely on software, XRoad is hoping you'll opt for a device that can also make phone calls and play music in addition to giving street directions.

The XRoad G-Map has eight map versions ranging from a one-time fee of $20 to $35.

To see our testers' first impression of the G-Map, see the Cars Blog post on the subject. Check back later for a review of Navigon's MobileNavigator app, also for the iPhone.