This paper introduces the concept of location-based publish/subscribe (LPS), which allows mobile ad hoc applications to anonymously communicate with each other depending on their locations. With this concept, publish/subscribe topics are typically expressed in a dynamic manner including proximity criteria, e.g., "I subscribe to all events on topic T published within some range R". We advocate that location-based publish/subscribe is a key programming paradigm for building mobile ad hoc application, and sketch our current implementation, which is based on standard APIs of the Java 2 platform, Micro Edition.