This document summarizes the debate around allowing cellphone use in classrooms. It traces the history of cellphones from their introduction in the 1980s to smartphones and the rise of BYOD (bring your own device) policies in schools in the 2010s. The document outlines arguments both for and against cellphone use, citing various studies on their impact on student learning and engagement. It also presents examples of classroom policies and systems that teachers have developed to manage cellphone use, such as the stoplight system and tools for student self-assessment of their phone habits.