NEW YORK (AP) - The big things have been taken care of: Y2K planners are confident the nation's power grid, telephones, banks and air traffic control system will run smoothly on New Year's Day. It's the smaller things they're not so sure about: local governments, small businesses and health care providers, for example. Even less is known about how many foreign countries will fare. "The smaller the entity, the greater the uncertainty," said Cathy Moyer of the Cassandra Project, a Y2K education group based in Denver. "There's great potential for isolated disruption and for some of that isolated disruption to spread around." For example, some experts have suggested that municipalities might send incorrect tax bills or schools might be unable to operate.