NEW: California and South Carolina could become the next states to limit cellphone use in schools, with state officials taking u

NEW: California and South Carolina could become the next states to limit cellphone use in schools, with state officials taking up the issue Tuesday. California Gov. Gavin Newsom is sending letters to school districts, urging them to restrict students' use of smartphones on campus. South Carolina's State Board of Education took up guidelines to tell local districts to ban cellphone use during class time, but postponed a final vote until next month to take more time to craft the proposal. Source: Police frequency