"Manager" is a power relationship. There are other ways to organize teams.

For example, at my last startup we had a shared vacation calendar and we'd just negotiate time off. We'd manage projects and timelines by discussion. We'd figure out who was working on what through short conversations every morning.

A major tomato processor has no power relationships; nobody can tell anybody else what to do:

http://morningstarco.com/index.cgi?Page=Self-Management

They're now putting together an institute to teach people their approach:

http://www.self-managementinstitute.org/