Nokia dominates a new list of greenest cellphones, followed by Samsung, Motorola and Palm products. Apple's popular iPhone scored in the lower half.

"Our highest-rated cellphones have energy-efficient chargers and are made of environmentally preferable materials," says a scorecard of 596 cellphones from 16 manufacturers by Good Guide, a company that rates products for their health, environmental and social impacts. The ranking says the top scorers are made by companies "implementing green production practices and takeback recycling programs."

Nokia makes 26 of the top 30 models, each scoring 7.7 or 7.6 out of a possible 10 points. Its C6 cellphone earned top honors overall. Samsung's Blue Earth phone came in 27th, followed by Motorola's Citrus and Ecomoto phones and by Palm's Pixi Smartphone.

Each of three tested Apple iPhones scored in the lower half, earning a 5.7 score. They did fairly well on environmental criteria, since the company has phased out the use of toxic chemicals from its devices, but Apple itself earned a below-average score for its "ethical policies and performance."

The lowest-ranking company is Research in Motion, whose BlackBerry phones earned an average 3.3 rating largely because of the company's environmental record.

Good Guide, started by Dara O'Rourke, a professor of environmental and labor policy at the University of California, Berkeley, offers these tips to consumers:

    * Avoid products that lack any information about their environmental attributes — this is a signal the manufacturer is not focused on improving the environmental performance of their operations and products. Only a small fraction of the cellphones on the market today promote any environmental feature whatsoever.
    * Be skeptical about manufacturer claims that they offer Energy Star certified chargers (this program for cellphone chargers recently ended), or chargers that simply say they're "efficient" with no supporting information.
    * Unplug your chargers when not in use, and look for chargers that disclose the efficiency of their chargers. Good chargers consume <0.15 W (<150 mW), while the best consume <0.03 W (<30 mW).
    * If you want to take precautions to reduce the amount of radiation exposure associated with cellphone usage, select phones that a) disclose an SAR value and b) have the lowest SAR values. Products with SAR <0.72 W/kg were found to be in the top 20% of products we examined.