When you're filthy rich and given the opportunity to hang out on the French Riviera for a week, what are you going to do? Walk the red carpet at Cannes? Take in a film premiere in an air-conditioned movie theater? That might satisfy your publicist, but if you're Bar Refaeli or Gwen Stefani, you'd probably rather hop on a million-dollar yacht and enjoy the sun. Why? Because you can.