The World's Longest Yard Sale is the flea market of your fantasies. For four days in August, Highway 127, running through six states, is converted into one 675-mile rummage opportunity. The game: Drive 30 seconds, pull over, browse, buy, get back in car. Repeat until exhausted. Jason Cochran went to rural Tennessee, where the sale was born and where it's still headquartered, to show you what a marathon of bargains looks like.