Forex Arbitrage
  
See: Foreign Exchange.
In France, you get 1.02 euros per dollar. But in Brazil, for some weird reason, you get 1.106 euros per dollar. So why not make .004 of a euro-dollar spread? Do it 8 billion times, and after tax on the gains for this forex arbitrage, you will be able to afford one grande latte. Arbitrage is a riskless trade, and good work if you can get it.
See: Arbitrage.