When is a sugar cube more than a sugar cube? For generations, California’s 4th graders have crafted virtual Spanish Mission models from sugar cubes, tooth picks, popsicle sticks, and construction paper… a rite of passage for kids from Eureka to San Diego. The Presidio Trust and Mission Dolores are co-hosting a new exhibit, Mission Possible (June 17 to 28, 2009 at the Presidio Officers’ Club).