There's little doubt that speculators, specifically commodity players, have a huge hand in the price swings of the items we use every day. The below article link suggests that as much of a quarter of the price of gasoline is due to speculators driving up the price of oil. That's not so hard to believe.
While the paper commodity market (aka futures) can be useful in some instances, for example to insure companies against price swings or smoothing out price fluctuations, it's ironic that most of the swings and fluctuations are likely caused by the futures themselves.
I'm not sure what can be done about the commodities markets. The capitalist nature of the markets is always resistant to regulation and control, instead placing its confidence in the markets' ability to self-regulate and self-correct.
Maybe so, but can vital and essential material necessary for life be entrusted to the vicissitudes of markets that are easily manipulated and corrupted? The prices of oil, rice, wheat, oranges, and pork bellies are so easily relegated to trading pits and people that never come in contact with what they buy and sell. But what if that self-correction doesn't come in time?