One of the rewards I used in my game for such a tournmaent:
Rod of Cantripical Power: This seemingly normal 2-foot rod of iron is a potent aid to all spellcasters who prepare cantrips (clerics, druids, and wizards). Once per day on command, a rod of cantripical of power enables the possessor to recall 1d3 0-level spells that she had prepared and then cast. The cantrips are prepared again, just as if it had not been cast. The rod can otherwise function as a +1 light mace.
Mild transmutation; AC 9; Hardness: 10, Hit Points: 10, Break DC 27; Weight 5lb.