This case study reports on collaborative design of an interactive artifact. The team works in the iLounge, which is designed and built with the purpose of supporting co-located collaborative work. iLounge is equipped with several horizontal large screens, called Smart boards, where the team members can make their contributions available to all others. We have studied how the students learn to use the electronic whiteboards in order to express their ideas, how the electronic whiteboards support them when making their conceptual design, and how they express themselves when using them. The results presents how whiteboards serve as a collective memory of earlier discussions and negotiations, it also gives the users opportunities for re-negotiation and re-representation of design proposals.