There are few things that say "summer" quite like a juicy slice of watermelon. Whether you're enjoying it at a backyard barbecue, packing it for a picnic, or simply standing over the kitchen sink trying not to drip juice everywhere, watermelon has a special way of making summer feel a little sweeter. Today, August 3rd, is National Watermelon Day, the perfect excuse to celebrate this beloved summertime fruit—and all the memories that come with it.  This day gives watermelon lovers ev …