You are correct, Kurgan, that the rosary is a useful form of repetitive meditation.  The twenty mysteries of the rosary cover the life of Christ from his Incarnation to his Ascension, with an appendix on the ultimate conclusion of Mary's life.  Personally, my devotion to the rosary was energized by Pope St. John Paul's 2002 encyclical which added the  Luminous Mysteries to the former three sets.