Mobile phones have emerged as an essential item of modern life. It is almost impossible to find an individual without one. Mobile Phone Symbiosis is about investigating what such a powerful and pervasive computer can be used to beyound its original purpose. Embedded sensors have delivered a smartphone that is a navigation system, compass, torch light, Personal Digital Assitant, etc etc. Applications have allowed us to personalise and extend the functions and usages of the device. This project is about investigating add-on devices that expand the smartphone. It is about the design of a telephone extension in the form of a symbiotic addition. The Symbiotic relationship can be either mutualism, commensalism or parasitism.