Human-centered design teams must integrate diverse individual perspectives into a shared understanding during conceptual design. The team's shared knowledge of their users becomes the basis for later design decisions. We conducted a formative study that shows how generic groupware is insufficient to support the transition from individual to collaborative creative work. We developed a set of design guidelines and implemented them in Dazzle, a collaborative shared display system for co-located design team meetings. Dazzle associates the action of showing information on the shared display with granting the rest of the team access to that information: showing is sharing. Dazzle also records a history of shown files. Team members can annotate this log using cross-platform synchronized clients. Teams of novice designers tested Dazzle over two consecutive sessions: the first focused on synthesizing user research, and the second focused on brainstorming. Dazzle was very effective at grounding team conversations about user research, but was used less for sharing information during brainstorming tasks. Items from the shared activity log were used as sources of inspiration and decision criteria during the brainstorming task. Future work includes additional support for active decision-making, and ambient feedback on design activity.