Agile Software Development with Scrum, Ken Schwaber and Mike Beedle. Prentice Hall, 2001.
Scrum explicitly relies on the emergence of a true team. By focusing on 30-day sprints, daily standup meetings, and management’s ability to remove obstacles, a team has an environment in which to flourish. There’s also the idea of a “Scrum of scrums,” which I think has the best potential for large-scale agile teams. (Reviewed Nov., ’02)