 Coming back to where we started the show, talking about retail. Yesterday, Kristen Schwab took us inside a UPS warehouse in Louisville, Kentucky, to get a better understanding of how online shopping has transformed the way companies store and ship goods. But what happens at the warehouse is only one piece of the equation. One- or two-day shipping often requires air travel, and most major logistics companies have their own airport operations. For UPS, that's Worldport in Louisville.