Coordinating the interactions of applications running on the diversity of both mobile and embedded devices that will be common in ubiquitous computing environments is still a difficult and not completely solved problem. We look at one such environment, an interactive workspace, where groups come together to collaborate on solving problems. Such a space will contain a heterogeneous collection of both new and legacy applications and devices. We propose the Event Heap, a coordination model most similar to tuplespaces, as being appropriate for such environments. We also present a prototype implementation of the Event Heap, and show that the system has performed well in actual use over the last two years in our prototype interactive workspace, the iRoom.