Collaboration plays an important role in the information seeking and retrieval activities within a team setting. In this research, we examined the impact of collaborative design features in two information retrieval tools that explicitly support collaboration. We designed the two collaborative information searching prototype, MUSE (Multi-User Search Engine) and MUST (Multi-User Search and Talk) and evaluated both systems. Results indicate that the communication (i.e., chat) function played an important role in enhancing the information seeking process by establishing common ground among group members. We also identified unexpected challenges that arose as the prototypes were used during these activities. These challenges were both technical and social in nature. We discuss implications for system design and directions for future research.