According to the United Nations, the world’s population reached six billion people on October 12, 1999. To mark this mind-boggling milestone, Population Action International (PAI), one of the world’s leading advocacy groups on population-related issues, has launched an interactive web site to help raise awareness of population issues, especially among young people. “Six billion is a remarkable figure, but numbers tell only a small part of the story,” says Amy Coen, PAI president. “We hope this web site will help people understand that caring about population means caring about individual quality of life—access to health care and education, a safe place to live, enough money to provide for one’s family, and a healthful environment.” Organized around the themes of health, education, and the environment, the site includes interactive maps that illustrate the availability of various resources around the planet, as well as suggestions for how teachers can discuss population with their classes. Teachers of younger children, beware: the site includes references to some mature themes, such as contraception and family planning.