Today's featured tip, submitted to our Best Travel Tip Contest, comes from Jan Schroder of the Girl on the Go travel blog, in which "Travel Journalist Jan Schroder Explores the Planet, One Drink at a Time." Her advice: "Find the best food and shopping in any airport with the amazing app GateGuru. I had a killer Reuben sandwich during a layover in Chicago, just by entering the airline code and terminal, then reading the reviews of different restaurants."...