The document discusses using QR codes in ESL classrooms. It provides examples of activities where students scan QR codes to access reading passages, vocabulary definitions, essay paragraphs, and clues in a scavenger hunt. The document advises shortening URLs when creating QR codes and testing codes before classroom use. Benefits of QR codes include saving time, convenience, excitement and variety in lessons, while a con is they are useless in classrooms without technology or internet access.