When Dick McDonald and his brother Mack opened a restaurant in California in the late 1940s, they had no idea they'd set in motion something that would not only change the way the world eats, but how it was served. Simon Calder travels from the suburban American crossroads where the fast-food revolution began, to distant foreign outposts of the golden arches, where a Big Mac is seen as exotic. Today, 60 years on, many competitors have arisen with flatteringly similar processing techniques. Is the gilt wearing thin on the golden arches? To what extent does the 21st century public still have an appetite for a mid 20th century happy meal?