The International Agency for Research on Cancer, an agency of the World Health Organization, produced scary headlines yesterday by warning that cell phone radiation might cause brain cancer. Tentative as it is, that suggestion contradicts the IARC's own $24 million study of a year ago, as well as the FDA and scientists who claim it's physically impossible. Everybody agrees more research is needed, but five billion people have taken to cell phones in less time than it takes many cancers to develop and grow. Will the WHO issue new guidelines? Should users take precautions on their own? We hear some conflicting opinions.