It all started with a joke.
Wrapping up a nationwide global warming tour, singer-songwriter Sheryl Crow posted a quirky "solution" online about a new way to save the environment.
She wrote: "I propose a limitation be put on how many squares of toilet paper can be used in any one sitting."
She told the joke to get people's attention, and it worked. Talk show hosts had a field day with Crow's comments.
"Have you seen my [backside]?" Rosie O'Donnell joked on "The View."
"It seemed like Sheryl was trying to be a little bit cheeky, no pun intended," said Michelle Lee, executive editor of In Touch weekly.
Maybe Crow was inspired by her ecoactivist partner Laurie David. After all, David's husband, Larry David, of "Seinfeld" fame, wrote the famous episode where Elaine says to a neighbor in the next bathroom stall:
"Three squares? You can't spare three squares?"
"No, I don't have a square to spare. I can't spare a square," the woman responds.
Crow wanted to clear the air about her comments.
"We're just so happy that people are talking about global warming, even if it's brought on by a joke," Crow told ABC News.
And for Crow and Laurie David, their message is everything.
They just wrapped up a successful cross-country ecotour of 12 college campuses to raise awareness about global warming.
The two started the trip in an environmentally friendly biodiesel bus at Southern Methodist University in Dallas, and ended the tour on Earth Day at George Washington University in Washington, D.C.
At George Washington, they joined musicians Faith Hill, Tim McGraw and Carole King and environmental activist Robert F. Kennedy Jr., who performed and spoke before a crowd of about 2,000 people.
Crow and David also talked with top White House adviser Karl Rove at the White House Correspondents Dinner Saturday night.
"How excited were we to have our first opportunity ever to talk directly to the Bush administration about global warming," Crow and David wrote on the Huffington Post blog.
"Much to our dismay, he immediately got combative," they said, "and it went downhill from there."
"We're definitely gonna be back," David said. "We haven't finished. This is something that's gonna be around for a long time."