Mobile devices often store data in reduced resolutions or custom formats in order to accommodate resource constraints and tailormade software. The Polyjuz framework enables sharing and synchronization of data across a collection of personal devices that use formats of different fidelity. Layered transparently between the application and an off-the-shelf replication platform, Polyjuz bridges the isolated worlds of different data formats. With Polyjuz, data items created or updated on high-fidelity devices--such as laptops and desktops--are automatically replicated onto low-fidelity, mobile devices. Similarly, data items updated on low-fidelity devices are reintegrated with their high-fidelity counterparts, when the application permits it. Polyjuz performs these fidelity reductions and reintegrations as devices exchange data in a peer-to-peer manner, ultimately extending the eventual-consistency guarantee of the underlying replication platform to the multi-fidelity universe. In this pap...