Approximately 75 percent of all retired cell phones are languishing in sock drawers because it’s too much trouble to dispose of them properly. A startup called ecoATM hopes to change that with a new service inspired by Coinstar””those pervasive kiosks in grocery stores that accept loose change and now process more coins than the US Mint produces annually. Plug your used mobile into an ecoATM and the machine assesses the resale value, collects the device, and spits out store credit, a gift card, or a charity donation. Battered old clunkers earn a few bucks; more recent flip phones in good condition are worth around $30; and a touchscreen smartphone like the Droid or iPhone can get you more than $150. “Two-thirds of the phones we collect are sold to domestic resellers and specialty refurbishers,” says ecoATM founder Mark Bowles. Phones with no resale value are shipped to a reputable metals reclamation facility in Belgium. There are eight ecoATM kiosks operating in malls and stores nationwide, and the company hopes to add 50 more by the end of the year. Dollars dispensed by ecoATMs thus far? Half a million and counting. Time to dig up that vintage Razr.