You've heard of eco-friendly cleaners, cars and businesses.
Add bikinis to the list.
Last week the Eagles cheerleaders were in Punta Cana, the Dominican Republic, creating the NFL's first "eco-sexy" calendar, according to Barbara Zaun, the team's director of cheerleading.
Each of the team's 38 cheerleaders was photographed in a natural setting - on the beach, alongside a stream, amid forest trees - while wearing makeup, swimsuits and accessories that are kind to planet Earth, she said.
The project was part of the club's "Go Green" program, which has worked recycling and alternative energy into the fabric of the club's daily operations, from biodegradable beverage cups to the solar panels atop the corporate headquarters.
The new calendar, which will go on sale in July, will use recycled paper - as tickets, programs and stadium toilet paper already do.
Vinyl records, CDs, computer cables, watch parts, candy wrappers and even old traffic lights were used to craft the jewelry and other accessories used on the shoot.
"Every item that you see cheerleaders wear is made out of the recycled, upcycled, or repurposed items," Zaun said.
Jennifer Kaiser, 25 - who also works as a financial systems analyst for the Defense Department - did her posing in front of a palm tree on May 4, the day the shoot began.
Only natural dyes were used to color the organic cotton used in her bikini, she explained. She sported a belt made of bamboo and recycled glass.
Other swimsuits were made of fibers from plastic soda bottles, and the Aaron Chang designs are reversible.
"So again, it's about living more simply and making choices that prevent additional waste," Zaun said.
Amy Mecca, 25, who also works as an operating room nurse at Methodist Hospital, had her ocean's-edge photo shoot at dawn on May 4 - after an hour-and-a-half hair-and-makeup session that started at 4 a.m.
The cosmetics were "natural minerals and natural ingredients," she said.
Besides her brown cotton bikini, she wore a big seashell earrings and a bamboo necklace.
Everybody on the squad is "really excited" about the eco-friendly theme, Mecca said.
"It's really going to be cool when the calendar comes out," she added, because a writeup with each photo will tell "the story behind each girl's outfit, each girl's accessories."
The calendar will cover 16 months - the football season plus next year.
No cheerleader will be left out, Kaiser said. The front and back covers, and pages of collages, ensure that photos of all 38 women will be included.
Zaun hopes the calendar helps spreads a message, and is more "just the latest fashion trend."
"We're hoping that this is seen as a cutting-edge calendar," Zaun said. "... I think it's important to know that every person can make a difference. ... We really do feel that if each person on the Earth takes these steps, we can reduce the harm that we're placing on the Earth."