Some in class work can be used as a reward. That is, there is some work that students actually desire to complete, but then again, I don't think that they see it as work.
Right now, the current theme in Mr. Agajan's class is imagination. As soon as you enter the classroom, on the wall closest to the door on the right and slightly above head level, he has big letters stuck to the wall that spell out "Imagination." Under this series of letters, there are several post its that the students posted. On these post its, students write questions that they had about a story that they just read. Whenever they write these questions, they first do a rough draft, and then they either bring it to me or Mr. Agajan to edit. After that, they rewrite it as their final draft and then post it on that question wall under "Imagination." They're given between 10 to 20 minutes to do all of this. It's rare that everyone finishes the rough draft, my or Mr. Agajan's editing of it, and their final draft all in one session, but some do.
For those who finish early, we give them more work to do. But, it's hardly work. They take one of those giant letters that spell imagination and they decorate it. They color it in and draw pictures in and around the letter that they select. They love it. I would guess that some of the students want to complete their questions so that they can decorate one of these letters. I assume that because so far, every student from every grade level that I've ever encountered loves to draw.