"Phones on Wheels" project comes from an assignment in Koji Yatani's class in grad school. it introduces interaction and applications using smartphones with kinetic capabilities. We develop an accessory module with robot wheels for a smartphone. With this module, the smartphone can move in a linear direction or rotate with sufficient power. The module also includes rotary encoders, allowing us to use the wheels as an input modality. We demonstrate a series of novel mobile interaction for mobile devices with kinetic capabilities through three applications.