Abstract. Data availability is an important issue in mobile computing environments. Both distributed data management systems and mobile storage devices, such as USB-flash drives, are used to allow users ubiquitous access to their data, but both solutions have their shortcomings. In this paper, we present the FEW Phone File System, a system designed to allow users to access their personal data independently of user’s location or machine’s connectivity. By combining the advantages of both mobile storage devices and distributed data management systems, the FEW Phone File System allows users to carry replicas of their data on their mobile phones, and access them as regular files in a file system, by relying on the wireless communications capabilities of these devices. To deal with the limitations of these devices, the FEW Phone File System integrates mechanisms that allows multimedia contents to be adapted to the mobile phone’s specifications, thus using much less storage. Additionally, the system includes a data source verification mechanism that keeps track of additional sources for each file (e.g. web, CVS/SVN repositories), thus allowing for these remote sources to be used as source alternatives for the user’s data.