1. A mobile terminal comprising: two or more sensors for sensing two or more types of context data; a sensor application program interface (API) for processing the sensed data to provide one or more context atoms relating to specific pieces of context-related information, wherein each context atom comprises an entity having an associated name, value, source, and date; a context engine for receiving and storing the context atoms, the context engine including a context silo for storing the context atoms and a context API for allowing one or more user applications to access the context data; a data store coupled to the context engine for storing information related to a user; a privacy engine for providing security; a communications manager for identifying context sources external to the mobile terminal and initiating contact with the external context sources; and a display for presenting the context-related information and/or information from the external context sources in the manner of a diary, wherein the context atoms are stored in a blackboard within the context silo, and the blackboard provides an API for querying and setting the context atoms.