We introduce a unifying file system abstraction, called a quFile, that provides a new mechanism for implementing mobile data management policies. quFiles allow arbitrary data types to be bundled together without confusing the user. Similar to a quBit (quantum bit), the particular data displayed by a quFile is not determined until the moment it is observed. A quFile displays the appropriate data type and version depending upon an application-specific policy that can take any information into account, such as the platform, external devices, context, connectivity, or battery power. We first describe what the quFile mechanism provides to applications and mobile devices. We then discuss how quFiles can benefit mobile data management in the areas of resource management, extensibility, and data consistency and availability.