SACRAMENTO, Calif. -- Standing in a mall food court, Marcellus Lang slipped a used cell phone into an ecoATM kiosk. Instantly, the machine scanned his phone, assessing its condition. Separately, it also snapped his photo, scanned his driver's license and recorded his electronic fingerprint.
For Mr. Lang's old Evo phone, he was offered $4. Repeating the process with an iPod Touch, he landed a $55 offer. Without pausing, the 25-year-old punched in his acceptance.
Within minutes, the machine spit out $59 in cash.
For consumers, an ecoATM is just one of a growing number of options for getting rid of old digital devices.
With the average consumer getting a new smartphone every 18 months, Americans are sitting on an ever-growing heap of digital discards. And many of those abandoned phones -- by some estimates, 800 million in the United States alone -- still hold some value, either as recycled donations or cold, hard cash.
Here's a look at some of the options for trading, selling or recycling:
TRADE UP, TRADE-IN? Plenty of major retailers, such as Amazon, Best Buy, Target, Radio Shack and Wal-Mart, will take your old cell phones -- and in some cases, computers, tablets, video game players and other devices -- and give you gift cards toward a store purchase.
With so many big-box retailers dangling trade-in incentives, "there's this great competitive environment that consumers can take advantage of," said Jeanette Pavini, consumer savings expert with Coupons.com, based in Mountain View, Calif.
Apple announced its own swapping program last month, letting consumers trade in their older iPhones for a discounted price on the new iPhone 5 models.
Not to be outdone, Microsoft also jumped into the trade-in game. Under two deals running through late October or early November, Microsoft will pay owners of "gently used" newer iPhones or iPads up to $200 -- to be used toward a new Windows phone or tablet.
CASH FOR PHONES: Companies such as Gazelle.com and USell.com enable consumers to sell their old electronics from their computer. In most cases, you look up your device, answer questions about its wear and tear condition, get a price, then receive a prepaid mail-in envelope for shipping the phone. You're paid once they receive the device.
Business booms every time Apple debuts a new phone, said Anthony Scarsella, chief gadget officer at Boston-based Gazelle.com.
Customers can lock in a selling price early, then take 30 days to hand over their old phone, so they aren't left smartphone-free until their new iPhone arrives.
Companies such as Gazelle either recycle the phones for scrap metal or sell them to wholesale refurbishers, who fix them up for overseas markets such as Africa, India and Southeast Asia, where demand is high for cheaper, used phones.
DONATE TO GOOD CAUSES: A number of organizations accept used cell phones as donations for various charitable causes. Among the better-known: CellPhonesForSoldiers.com, a nonprofit that recycles donated phones and uses the proceeds to supply U.S. soldiers overseas with free international phone-calling cards and other services. Donors, who can drop off their phones or ship them directly, get a tax donation receipt based on the phone's value.
The Ohio-based company, started by two teenage siblings in 2004, recently launched an iPhone buyback program, with prices ranging from $14 for an older-model iPhone 4 to $326 for an iPhone 5.
Another is Phones4Charity.org, which acts as a fundraising tool for charitable groups such as the Red Cross or the National Wildlife Foundation. Individuals can get a tax receipt for donating phones, or a charity group can collect phones and be reimbursed in cash.