The Mobile Experience Lab will introduce the Logger, a data logging platform that includes both hardware and software components. The platform enables users to build and connect sensors together in any configuration. This system allows a user to log biometric data as they walk through the urban environment. It is coupled with a web based visualization system that allows data to be uploaded and visualized by any user connected to the Internet. We have used open hardware and software to build an easily distributed and fabricated data logging system. The Logger is one of many components from a long running SSHRC project titled Biomapping, which explored the development of process-based maps, to question the sense of self through biometric technologies. The Logger is symbolic of larger questions around the politics of data and technology.