Some teachers are masters of delegation. Simple classroom jobs are delegated to students. These teachers realize two important concepts:
A teacher cannot do it all. Delegating those things which a student can do and do well leave more time for the teacher to do those things which require his/her expertise.
Allowing students to help with running the classroom gives them a "stake in the program," gives them a sense of ownership, and builds responsibility.
In Organization Made Easy!, the chapter entitled "Focused or Fragmented" examines this concept. Read about how two elementary teachers structured systems giving every student responsibility. Read tips on how something similar could be used in secondary schools.