John Bytheway gave a fireside called “The Best 3 Hours of the Week.” It is available on DVD from places like Deseret Book. It is a great talk that gives suggestions for youth to get more out of their Sunday meetings. Brother Bytheway gives a particularly enlightening description of the symbols and covenants of the sacrament. The fireside is about 75 minutes long, which will fit into a mutual activity as long as you start on time. Ice cream sundaes are optional, but the name goes along with the sabbath theme.