A multi-source picture viewer adapted for use within a portable electronic device to view pictures saved on multiple sources, comprising a common graphical user interface for providing picture viewing functionality that is independent of the multiple sources, an optional domain-specific graphical user interface for providing source-related picture viewing functionality that is dependent on the multiple sources, and an image-fetching transport layer for retrieving pictures from the multiple sources and converting the pictures to a common picture model for display on the portable electronic device under control of the common graphical user interface and further manipulation via the domain-specific graphical user interface.