This paper describes work in progress developing a context-aware meeting alert. This application integrates semantic web technology in RDF (for representing calendars), semantic web rules (for making a context-dependent decision about the precise timing of the alert), and mobile technology for location sensing and message delivery. The outlined work is an early experiment seeking to demonstrate the feasibility of applying efficient, semantically sound semantic web reasoning to mobile applications. 1 MOTIVATION Computing is moving towards pervasive, ubiquitous environments in which devices, software agents and services are all expected to seamlessly integrate and cooperate in support of human objectives, anticipating needs and delivering services in an anywhere, any-time and for-all fashion [23]. Pervasive Computing and Ambient Intelligence are considered to be key issues in the further development and use of Information and Communication technologies, as evidenced, for example, by the...