This document discusses ways for libraries to build relationships with teens using social media and mobile technology. It recommends using Facebook to promote teen events and programs since teens frequently access Facebook from their phones. Flyers should appeal to teens and be posted in local stores. Creating a Teen Advisory Group allows getting feedback on events. QR codes, check-ins, augmented reality, and mobile apps can help libraries engage with teens in a digital world. Overall, embracing social media and mobile technology helps libraries connect with teens where they are already active online.