Gas Hedging with ETFs

Greg Newton wrote an interesting piece recently about using an ETF to hedge your gas consumption.

You can read his post for full details, but the gist of his idea is to buy shares of the recently available oil ETF such that if gas prices go up, you'll offset your car's gas bill by an increase in value of your oil ETF. I've been thinking about this idea on and off for a good chunk of the day and I can't find any flaws. I'm almost inclined to give it a shot myself. Almost.