We have always included a memory verse for each Rotation lesson.  Every Sunday the memory verse is discussed and explained as part of the lesson and our children receive a memory verse sticker to take home at the end of Sunday School.  Attached is our list of Memory Verses for this SS year and the dates the children can say it for a prize.  This list is given to the parents at the beginning of the year and also emailed to them.  When we first began Rotation we did not include a prize for memorization.  However, our Christian Ed committee thought that a prize might be fun for the children.  So I began to include a prize and a time frame in which they can say the verse.  The children seem to like the incentive of the prize.