It was, as things go, an eventful seven days. Last week brought two announcements that, depending on how you view them, were either high points or hype points.

First up was the Bloom Box, a device unveiled, with much ado, by a Silicon Valley firm called Bloom Energy. The $700,000 gizmos provide onsite power using fuel-cell technology. Fuel cells aren't exactly new -- indeed, their discovery dates to the 1830s -- but this one was significant by virtue of its first few customers. The company announced that eight major firms -- including Coca-Cola, eBay, FedEx, Google, and Walmart -- had purchased the devices, providing a level of heft and hype not typically afforded such start-ups. Our managing editor, Matthew Wheeland, tells the story and follows up with some perspective on whether these are good investments.

The other big story came from Walmart, which announced an ambitious program to cut climate emissions -- or, rather, have its suppliers to it for them. With 90 percent of its carbon footprint embedded in its products' supply chain and lifecycle, the company plans to focus first on the sectors that are likely to yield the greatest amount of emissions reductions as well as the greatest amount of cost savings, beginning with apparel, food and energy-consuming goods. Senior Contributor Marc Gunther provides his always-trenchant perspective on the move, while Elizabeth Sturcken, managing director of Environmental Defense Fund's Corporate Partnerships program, who worked closely with the retailer on this initiative, offers her insider's view.

Walmart wasn't the only retailer to make news. Best Buy joined 15 other companies already pushing for climate and energy legislation as part of the Business for Innovative Climate and Energy Policy (BICEP) coalition. The group has been pushing a set of nine principles to call for U.S. legislation that creates a national renewable energy standard, sets short- and long-term greenhouse gas reduction targets and establishes a cap-and-trade system with 100 percent auction of carbon allowances, among other points.

And more: The nonprofit group Climate Counts named its first group of "Industry Innovators"; a new ranking calculated chemical companies' "sustainable value creation"; another industry ranking assessed the sustainability performance of the information and communications technology (ICT) sector; Marc Gunther unwraps Quiznos new green packaging; and Apple spent about a third of its annual meeting discussing sustainability, melting glaciers and the finer points of reporting about greenhouse gas emissions, according to shareholder activist Conrad MacKerron.

The economy may still be bottoming out, but the world of green business continues to grow unabated.

To help marketers and advertisers avoid the mistakes of vague, non-specific or misleading environmental claims, the International Chamber of Commerce has produced a new global Framework for Responsible Environmental Marketing Communications.

This Economist Intelligence Unit report discusses why firms are embracing sustainable practices, how companies are embedding corporate social responsibility into their businesses, and how they are gauging and reporting their success.