This is Jim Rogers idea and his index, but I think this is a good long term investment for the following reasons: (1) people need to eat and the planet's population keeps growing, (2) as the emerging markets become wealthier the trend seems to be to eat more meat which further pushes up demand for food, (3) if you are in the US like me, then the dollar seems sadly to be headed south for the near future due to low interest rates and debt....and commodities seem a nice hedge against inflation, and (4) Jim Rogers seems to be right more often than he is wrong.