The week of April 6 to 12 has been designated National Cell Phone Recycling Week by the EPA. And it’s not too late to participate in this national event by donating or recycling unwanted cell phones, PDAs and their accessories—though we know you already recycle your old mobile devices, right?

Well … er … actually, despite the large number of programs, most consumers still do not know where or how they can recycle their cell phones. Consequently, only 10 percent of unwanted cell phones are recycled each year.

The EPA says recycling your cell phone can help to save energy and keep useable and valuable materials out of landfills and incinerators. Cell phones are made from precious metals, copper, and plastics—all of which require energy to mine and manufacture. According to the EPA, if all of the 100 million cell phones ready for end of life management in the U.S. were recycled, we would save enough energy to power more than 18,500 U.S. households with electricity for one year.

OK, enough of the preachy stuff. So what can you do this week?

The EPA’s Plug-In To eCycling partners AT&T, Best Buy, LG Electronics, Motorola, Nokia, Office Depot, Samsung, Sony Ericsson, Sprint, Staples, T-Mobile, and Verizon Wireless are all sponsoring events.

And you can find drop-off and mail-it-in information here.

All the major carriers—Verizon Wireless, AT&T, T-Mobile and Sprint—will accept old phones at the stores. And some do year-round.

The OC Register’s Gadgetress  also offers some resources and tips, such as the following

Three things to do before you give up your phone:

1. Terminate service.
2. Clear the phone’s memory by hitting the reset button or use a data erasing tool online, such as ReCellular’s free Cell Phone Data Eraser.
3. Don’t forget to remove the SIM card.

Steven Castle - Contributing Writer

Steven Castle is Electronic House's managing editor. he has been writing about consumer electronics, homes and energy efficiency topics for two decades. He is also the co-founder of GreenTech Advocates.