I wanted to pass on the most effective method I have used to counter the opportunities for cheating. When I prepare an exam for a weighted assignment or topic I always prepare a version "A" and "B". Students in close proximity get different tests and I have less wandering eyes. Students who have to "make up" an exam are given a "C" version so the exam does not get passed on from others. (version "C" is usually quite different but still on same materials covered) I hope this helps others to use this method to keep students honest.