The mobile phone has become part of our everyday lives with astonishing speed. Over four billion people now have access to mobile phones, and this number keeps increasing. Mobile media technologies shape how we communicate with each other, and relate to the world. This raises questions about their influence on identity. Medium-specific properties and user-practices challenge the idea that we understand ourselves through stories. It is proposed that the notion of play sheds new light on how technologies shape identities. The (...) mobile phone mediates identities on four play levels: we play on the mobile, with the mobile, through the mobile, and at the same time we are played by the mobile. Mobile media bring new freedom of movement. Yet at the same time they constrict us. In this dialectic we become moving circles. (shrink)