thirds of all parents are concerned about their children seeing potentially harmful things on the Internet. That includes pornography as well as deceptive or manipulative e-mail.\nThe survey, conducted by NFO Interactive, a research firm, was disclosed Tuesday (June 23) at a conference in San Francisco on children's online issues. Among other things, the study found: --More than half of American parents said they would pay for services that filter Internet content and chat.\n--Two-thirds of parents do not allow their children to give out personal information, 62 percent prohibit online shopping and 54 percent have taken steps to keep their kids from surfing to adult entertainment sites.\nAnother study reported at the conference said e-mail was the most common activity engaged in by children on the Internet. After that, the next most popular activities were general Web surfing, homework, games and chat.