The paper discusses the relations between Ubiquitous Computing (UC) and cooperation pointing to two reference scenarios. UC technologies are still in a early stage: however, it is possible to envisage an evolution that makes smart objects pervasive in work settings. Under the hypothesis that these objects are likely to have very a specialized functionality, the smart environment has to possess distributed inferential capabilities to complement them toward an adaptive support to both individual and collaborative behaviors. CASMAS is a model informing an architecture to design collaborative UC environments: it combines inference capabilities with the management of contextual information that is modulated according to the structure of physical and logical spaces.