The "design collaboratorium" is a new usability practice that has been developed in an action research project between three industrial usability labs and a university. The design collaboratorium has been developed as a reaction to the failing capabilities of classical usability methods to cope with ubiquitous technologies. It has borrowed elements from participatory design and developed them further to become useful in large-scale industrial development organizations. The design collaboratorium will be presented through examples from a joint project: a vision project concerning wastewater treatment technology. In light of the case, we will discuss the philosophy underlying the design collaboratorium in further detail: the collaboration between active participants, the role of design artifacts, and the room as a meeting ground. Finally we lay out the working method and propose directions for future usability competencies.