Knowledge Creation (KC) is a critical activity inside organizations. It has been said to be a differentiating factor and an important source of competitiveness. Tacit knowledge is an important asset of any organization. Because it is not formalized is difficult to share. KC supporting systems help people inside an organization to share this tacit knowledge. This paper presents the design, and implementation of a KC system called MCKC, for Mobile Collaborative Knowledge Creation, supporting face-to-face knowledge creation and sharing in mobile scenarios, allowing people to create new knowledge and share their tacit knowledge with their co-workers, using visual metaphors, gestures and sketches to implement the human-computer interface.