From Ken Alford:
After giving them plenty of advance notice, invite the entire bishopric or branch presidency to scripture chase against your class.
You can set up the rules anyway you’d like — making it as competitive or just friendly, as you’d like.
Depending on the parents of your students, you might also be able to try something like this using Seminary parents and students. An activity like this tends to provide positive learning incentive to both students and visitors.