Now, DonorsChoose has created new possibilities and amazed smiles on a classroom full of lower-income 4th graders.
"DonorsChoose has funded for each one of you to receive a recorder" said "Miss Temple" to her kids, gathered expectantly on the rug, as she unpacked the newly arrived box and handed them out.
"These are yours to keep" she told them -- to their obvious surprise. "You can perform in front of the school. Maybe some of you would go to church to play."
Excited gasps ran through the little crowd on the rug, unexpected possibilities dancing in their minds' eyes.
As the children began to explore which fingers go over which stops, and just how hard they should blow -- it sent up a sweet cacophony. Miss Temple told ABC News, "We have no band, no elementary music class. The children need the opportunity to see if they're interested."
Many of the teachers in this Mississippi public elementary school have found that, if they keep the thank you letters coming, the return may be a cornucopia of teaching tools.
"My rug is the first thing that came in. You should have seen their faces when they walked in -- because it brightened the room!" First grade teacher Tammy May told ABC News. "And this is a lifesaver: My own copy machine for my class -- and someone has so graciously funded this for us!"
First grade teacher Yolanda McDowell said she was as skeptical as many first-time donors -- at first.
"I thought maybe it was a gimmick, and I tried it," she said. "And when my first proposal was funded, I was like, 'Yes! It works!' And so I wrote five more, and they all have been funded."
She's not alone, as Charles Best says, and as can be seen online at DonorsChoose.org on his financially transparent "Impact" page.
"Today, 23,000 public school teachers from different parts of the country have posted proposals on our site," he said, "and donors from all 50 states have fully funded 25,000 projects on our site. And that channeled $12 million of books, art supplies, technology, field trips to more than half-a-million students from low-income families."
Best has resisted the temptation presented by many admirers who have urged him to grow quickly beyond schools.
For now, he is focusing on how to carefully set up his next step -- giving teachers in all 50 states the chance to submit project proposals for their classroom's "micro-solutions."
There's clearly great need out there, both in poor rural and inner city schools -- like Brooklyn's P.S. 75, where something as simple as bright new rulers brought smiles.
It's about more than just the badly needed new rulers, 4th grade teacher Patie Hart explained to ABC News while her kids worked on their thank you letters.
"It teaches them a lot of skills -- how to be thankful for the things that they're getting; that everything in life is not free," she says. "This opens their eyes and enlightens them a little bit to say, 'Someone is paying for it, and I need to thank them.'"
It's not only the teachers and children who are thankful, as Gail Christensen in New Jersey made clear.
"If you can use even limited resources -- skip the latte this week, or skip something, give to something greater than yourself -- you get far more back than you do from the actual dollars sent out," she said.