In my classroom economy, there are paid jobs for which the students are responsible for completing each day. Here are some jobs that my students have held in my classroom over the past few years.

Teacher Assistant - completes all secretarial jobs that need to be done.
Messenger - takes notes to the office or runs errands around the school.
Homework Checker - checks in students' homework and reports missing assignments to the teacher.
Librarian - keeps book shelves organized.
Computer Technician - turns on and shuts down classroom computers
Equipment Manager - keeps track of playground equipment
Payroll Clerk - issues checks to students at the end of every pay period (Of course the teacher will have the sign the checks)
Travel Agent - keeps track of field trip permission slips
Meteorologist - gives daily weather report to the class
Mail Delivery Person - passes out notes to go home with students in cubbies or mailboxes

Learn more about my classroom economy here.