motivational techniques

I think one of the most powerful motivational tools we have is clear and focused feedback on student behaviors.  I love being able to "catch" students being really on task, working hard etc. Noticing this and verbalizing what is favorable about the student's behavior is very powerful, not only in building that child's esteem, but also in reminding others what the expectations are.
Another more concrete motivator I love to use is the stylus for the Promethean board.  If I remind students that I will be looking for someone to show their work for us on the board or a volunteer to navigate an interactive activity for us, students are suddenly very interested in getting their own worm done.  Everyone wants a turn to write on the board :).