You can hedge against the rising price of gas by purchasing something like an Exchange Traded Fund (ETF) through any brokerage (ie Vanguard, Schwab, E*TRADE). Something like this index fund will rise and fall with the price of oil & gas. By doing this, you will also be ensuring some losses if gasoline prices decrease. Remember that the prices of oil stocks reflect the expectations of future prices which means that there is a certain amount of increase that is already figured into the price of these stocks.
ISHARES TR DJ OIL&GAS EXP (IEO: NYSE)
The investment seeks investment results that correspond generally to the price and yield performance, before fees and expenses, of the Dow Jones U.S. Select Oil Exploration & Production index. The index measures the performance of the oil exploration and production sub-sector of the U.S. equity market. It includes companies that are engaged in the exploration for and extraction, production, refining, and supply of oil and gas products. The fund uses a representative sampling strategy to try to track the Index. It is nondiversified.
As you can see, there has been about a 20% increase in the price of this ETF since the beginning of this year which corresponds, somewhat, to the increase in gasoline prices (and natural gas prices) over the past few months. Had you owned some of this ETF in January, you could sell it now for 20% more and pay for the increase in your fuel cost over this time.
It's a little hard to say exactly how much of this you would have to purchase in order to hedge against the increase in yours & your family's gasoline/heating oil consumption but the math is doable. This isn't very good for short-term budgeting because you would have to buy some of this ETF with cash and you wouldn't realize any gain untill you sold it. It's really more of a long term strategy to say that whatever else happens, it won't cost me any more than $XX, overall, if gas prices increase.