Though many of those phones will find a dusty home in a cluttered desk drawer, millions could wind up in landfills, leaking toxic metals and chemicals into the ground.
Many old phones get refurbished or recycled under donation programs that help charities, but it's a tiny fraction of the 100 million or so handsets that are already "retired" each year in this country, according to a new estimate from the environmental research group Inform Inc.
And now, the number of retired cell phones is expected to grow sharply.
The new rule that takes effect Nov. 24 allowing users to change wireless companies without losing their phone numbers is expected to motivate as many as 30 million people to switch within the first year.
Those who do will need to buy new phones. That's because even carriers that use the same network technologies employ different encryption.
So what will become of all those old phones?
While the industry has just launched a new initiative to publicize recycling, existing efforts by individual wireless companies with collection boxes in their stores have so far mustered only modest success.
And even those phones that are refurbished raise environmental concerns because they still may eventually end up in the garbage, especially if sold in poorer nations with no recycling programs--as the majority of refurbished phones are.
A better answer is for cell phone makers to change the way they make their devices, assert environmentalists including David Wood, executive director of GrassRoots Recycling Network in Madison, Wis.
Some such changes may come to this country as a result of a new directive passed this year by the European Union, whose computer recycling requirements helped spur U.S. companies to offer takeback programs. The new EU rules will require makers of phones and other electronics to eliminate lead, mercury, and brominated flame retardants from new products by mid-2006.
Since most phone makers sell their products globally, it may be more practical financially to use the same manufacturing processes for all markets. While the big players concur with that idea as a general concept, none will comment on their specific plans regarding the EU directive.
In the meantime, most efforts are focused on extending the useful lives of old handsets and recovering potentially harmful chemicals from those that no longer work.
Several million used handsets are now being refurbished or recycled each year. Proceeds from resold handsets and recovered raw materials go to charities such as Call To Protect, which aids victims of domestic violence.
But the overwhelming majority of the 100 million handsets retired each year are seemingly either tossed in a drawer or the garbage. How many go in either direction is anyone's guess.
Much like computers, even relatively new cell phones have little resale value.
For years, wireless companies have been practically giving away handsets with ever-newer bells and whistles as a lure to potential customers or an inducement to stay for existing subscribers who may be eyeing a new carrier.
As a result, judging from current auction listings on eBay, those determined enough to sell a used phone can expect to bring in as little as $5 per handset.
But if the used phones on display at a typical tag sale are any indication, many seem to prefer a drawer as at least a temporary resting place--possibly because they may worry about pollution, or perhaps they simply find it hard to fathom how a cell phone that worked perfectly fine just yesterday is suddenly worthless.
"If you were to call and talk to 10 people, you'd probably find that two-thirds of those people have handsets sitting idle in their garages," said Eric Forster, vice president of marketing and sales for ReCellular Inc., a Dexter, Mich., company that refurbishes or recycles old handsets collected by cell phone carriers.
The good news, Forster said, is that "people know they probably shouldn't throw it away" because it may harm the environment. "But they're not sure, so they keep it."
Of the phones received by ReCellular, which also buys old handsets, about 75 or 80 percent are refurbished at an average cost of $20 per handset and then resold for about $45 or $50. A portion of those proceeds often goes to charities.
Those phones that can't be salvaged are sold for between 50 cents and $1.25 per pound to recycling companies that extract toxic materials for either reuse or safe disposal.
Most of the toxic substances in cell phones are contained in the circuit board, the liquid crystal display of the screen, and the battery.
But while efforts to recover those substances are intensifying in the United States and Europe, recycling programs are far less developed in poorer nations--where three-quarters of ReCellular's handsets are expected to be sold next year.
"Exporting waste is not the way to resolve waste problems," said Eric Most, director of the solid waste prevention program at Inform. "We need to work with industry to change the design of phones to make them more reusable and recyclable and less toxic."