If you find yourself in a dark alley in Istanbul, remember Rule #17: When in a dangerous or threatening situation, claim that you are from Texas. To keep customs agents from laughing at you at immigration, heed Rule #6: Do not take a passport picture when you are hung over. These and 27 other (sometimes unconventional) rules to follow for working-class globetrotters when visiting some of the most famous cities around the world...and learn how to visit them for under $2,000 per destination.