Multi-agent systems are encountered in nature (animal groups) in various domains of technology (multi-robot networks, mixed robot-human teams) and in various human activities (such as dance and team athletics). Information exchange among agents ranges from being incidentally important to crucial in such systems. Several systems in which information exchange among the agents is either a primary goal or a primary enabler are discussed briefly below. Specific topics include power management in wireless communication networks, data-rate constraints, the complexity of distributed control, robotics networks and formation control, action-mediated communication, and multi-objective distributed systems.