Some of the world's highest profile humanitarian and ecological campaigners convened in New York this week for Bill Clinton's annual philanthropic conference.
Queen Rania of Jordan, U2 singer Bono and former US Vice President Al Gore were among those taking part in discussions about pressing global issues such as climate change and poverty.
Since leaving office in 2000, the former US premier has worked hard to do something tangible about worldwide problems he views as serious threats. He established the Clinton Global Initiative four years ago to draw attention to such issues.
Seated next to Mr Clinton, Queen Rania spoke passionately about an education programme she has overseen in Jordan to renovate more than 500 schools in five years. "Education is not just the responsibility of the government," she said. "It's everyone's responsibility."
Generating huge applause as he took to the stage to speak was Lance Armstrong. The sports star, who is planning a return to professional cycling and next year's Tour de France, said his foundation will commit $8 million over the next five years to a global awareness campaign for cancer. He said he hoped his return to competition would continue to focus the spotlight on the disease, which he battled in 1996.