Yes indeed, both oil and gold are extremely volatile, so a balance has to be struck between which resource has the better longer term predictability. This predictabilty is certainly in oil and gas at the moment, as we do believe that these highish prices are sustainable in the longer term given the economic outlook and future shortage of natural gas. However, gold is an insurance policy and it is insuring the portfolio against perceptions of inflation, a weakening US dollar and a fall in Wall Street. It is the speculative demand from sophisticated investors that causes the gold price to accelerate, whilst the jewellery demand keeps it in a narrow trading range. So no, it is not a clear indicator anymore of the state of the world economy.
Platinum is certainly a metal whose growth in consumption is going to continue.
Yes, a minor amount is used in electronic circuitry, but the major consumption at the moment is split between jewellery and in use in the autocatalyst in motor vehicles. The future really lies in the production of electricity through the use of the fuel cell. This is being pioneered by Ballard and others, and the consumption of Platinum will increase many times. The other platinum group metal Palladium, has also a reasonable future, but not to the same extent as Platinum. Platinum production comes principally from South Africa, and the country has the hundreds of years supply at the right metal price to supply to new uses.