Boston's favorite holiday, Patriots' Day celebrates the first battles of the Revolutionary War, the Battle of Lexington and the Battle of Concord, the site of that "shot heard round the world." Today, April 19, is the "official" Patriots' Day (and the day on which the battles were fought in 1775), but the holiday is officially celebrated on the third Monday in April. Aside from the Boston Marathon and Sox game Monday, this weekend brings us......