Although the growth of the Web has brought widespread recognition of the potential of search, not all of the information that comes into our purview is actively sought to meet a clearly defined need. Information is often simply encountered in the course of our everyday activities; as such, it may not be immediately useful. Rather, it may have potential merit as a reminder, for its evocative qualities, for its educational value, for the ideas it spurs, for its potential utility as a reference, or as something to share. Deciding what to do with encountered information—whether to keep it and if so how—represents a key challenge for the field of personal information management (PIM).