BottleRock held its inaugural festival last weekend at Napa Valley’s Expo Fairgrounds under a scorching sun, but the heat wasn’t enough to keep the crowds away. Downtown Napa Valley became BottleRock Central, swarming with crossing guard-policemen and retailers pushing their goods, and in many cases, their parking lots. Nearby neighbors set up pizza and lemonade stands and signs dissuading BottleRockers from urinating on their lawns.