Although coupling interaction resources is key to ubiquitous computing, this notion has been overlooked in previous studies. In this paper, we address this notion in a more systematic way by describing coupling as a finite state machine whose states should be maintained observable and controllable by users in a flexible and reliable manner. We illustrate the discussion with state of the art demonstrators as well as with I-AM, a middleware that supports the dynamic construction of multi-screen, multi-keyboard, and multi-pointer interactive spaces. CATEGORIES AND SUBJECT DESCRIPTORS : D.2.2 [Software Engineering]: Design Tools and Techniques – /User Interfaces./, H.5.2 [Information Interfaces and Presentation]: User Interfaces. GENERAL TERMS: Theory, Human Factors KEYWORDS : Interaction resources coupling, interaction technique, ubiquitous computing.