Making Things Happen

Good project managers make it their business to know all kinds of useful things about state of the team, state of the world and then apply that knowledge to help people get stuff done.
Social networks (People talk each other) always stronger than technological ones.
The big challenges like project vision, feature lists, and schedules always come down to lots of little challenges that are positively influenced by how easily good knowledge and information flow through a team.
Project managers play a critical role in making that flow active and healthy.