The troops in the sandbox like to call home and talk with their families. Cellphone calls from Iraq are expensive. (Thanks for supporting the troops, Cingular, ATT, Sprint, T-Mobile, Verizon. Those are your customers over there.) One soldier struggled to pay off a $7,000 cellphone bill, and this prompted two Norwell, Massachusetts teenagers, Brittany Bergquist, 16, and her brother, Robbie, 15, to do something about it.

They collected $14 from their piggybanks, got school friends to kick in another $7, and started a bank account. The bank added $500 to the account, and their non-profit was on the way. The next steps were a bake sale, a yard sale, and a car wash outside their Town Hall.

Their plan to help that one soldier broadened when the pair heard that recyclers paid for used cellphones. They began by asking friends for old phones. Within weeks, Brittany, Robbie and their parents had persuaded local shops, police stations and government offices to set out recycling bins.

Three years later, the Bergquists’ recycling network spans more than 4,000 drop-off sites located in every state and in England, Canada and Japan, and yields some 20,000 cellphones a month, which fetch an average of $5 each from a Michigan recycling company that refurbishes them for resale.

The shipments from Cell Phones for Soldiers are “an equivalent quantity to what some of the national chains are bringing in from their customer recycling programs,” said Mike Newman, a vice president at the recycling company, ReCellular Inc., whose clients also include Sprint, Verizon Wireless and Best Buy.

What a tremendous idea. The Bergquists have shown more adulthood and sense than many people more than twice their age.

With the recycling proceeds and some cash donations, the Bergquists buy phone cards worth up to 60 minutes each in international calls. They send the cards to service members and their families or military units that place requests through the charity’s Web site, cellphonesforsoldiers.com.

Nearly 400,000 cards have shipped. That number is expected to grow sharply over the next few months, when AT&T Inc. makes a few hundred of its Cingular stores nationwide official drop-off sites.

A tip of the too-small Kevlar helmet to Ariel Sabar who wrote this story for the NY Times