Bring your grill to medium heat and set the rack about 4 inches above the heat source. Roll or lightly press each dough ball into a flat round, lightly flouring the work surface and the dough as necessary. Let the rounds sit for a few minutes; this will relax the dough and make it easier to roll out. Roll or pat out the dough on a well-floured pizza peel, as thinly as you like, turning occasionally to prevent it from sticking.
Place the dough directly on the grill. Grill until nicely browned on the bottom, about 5 minutes. Brush with olive oil and turn; brush again, then top with salt and rosemary, drizzle with a little more olive oil, and grill, with the grill top down, until the bottom is brown and the top is hot. Serve immediately or at room temperature (these will keep a few hours).