I have personally witnessed two teachers use this in their classes and it works exceptionally well.  The novelty will wear off after time, but it works well for students at this point in the year when summer break and friends are all that is on children’s minds.

1. Buy a feather boa.
2. Tell your students to put their heads down on their desks and close their eyes.
3. Tell them when you pass by and touch them with the feather boa they can line up.

This seems to have a magical effect because feathers are quiet and those who are in line are in suspense waiting to see who will be feathered next.