Most of us have the green back-to-school vibe going by now.

We got the BPA-free water bottles and the reusable lunch sacks and the organic Trapper Keepers.* The kids are ready to recycle their homework and compost their art projects. We have been sternly warned not to let our engines idle while waiting in the pick-up line on a rainy day.

But the newest green frontier is truly a sacred cow -- and I don't mean hemp-colored vegan Crayolas. Environmentalists have set their sights on the traditional back-to-school wardrobe.

A new movement of clothing swappers are saying that that to be a truly green family, you gotta go used.

The stigma of used clothing is fading away, says thredUP co-founder James Reinhart. His Cambridge-based company is a web-based children's clothes swapping system -- you pay a small fee and trade a box of your child's (clean and washed) outgrown clothes for a box from someone else. Users rate each other ebay-style, and the company insists you only swap stuff in good condition.

It's not only a bargain to swap clothes, when kids outgrow them every six months, but its fast becoming chic, he said.

Really? When I was a kid, you couldn't have pried my (new) Esprit, Ton sur Ton, and Guess duds out of my shallow fifth-grade hands.

But that was the wasteful 80s, when labels were a must-have status symbol. Are today's kids so much different?

It appears so, and clearly their parents are, said Reinhart.

"We are in the midst of a powerful consumer shift - increasingly, eco-consciousness is in," he told Moms Are Talking About recently.

"The hesitation around the used clothing industry has rapidly begun to dissolve - not only because it's an affordable option, but also because it's environmentally responsible," he said.

"Parents who otherwise wouldn't go the "gently used" kids clothing
route, are starting to reconsider. It's the green angle that has parents thinking swapping above all else, and we're thrilled to be at the forefront of this consumer shift."

The past month has brought nearly 100 new customers to thredUP per day, he said.

"They are excited to push back against the "buy, buy, buy" mentality of marketers during this season, and swap with other environmentally conscious families across the country," Reinhart said.

What do you think? Would your kids consider used clothes for their back-to-school wardrobe? Do you think buying a brand-new clothes for growing children is environmentally irresponsible? Leave a comment and tell us what you think, and follow Moms Are Talking About on twitter at @ericanoonan

* P.S. Just kidding about the organic Trapper Keeper. There is no such thing.