Hell, if I knew the answer to that question I would be one rich dude. I do know that we are headed for higher prices. The USA is worse off than Canada because we have oil. ( Canada is the country that supplies the USA with the most imported oil ) The Canadian dollar is sort of like a petro-dollar, we are some what protected from world oil prices. We also have not printed significant amounts of currency to prop up our economy, Where are the USA has just printed a trillion extra dollars and they also have the burden of the Afganistan and Iraq conflicts to pay for and have been paying for many years. Not to mention the sub-prime banking crisis and bail outs of the big 3 USA auto makers and the AIG mess.
Just as quick as prices came down from $4 plus a gallon it may go up as fast to retest the highs and may even surpass those prices per gallon. The US dollar will no doubt be devalued and the Canadian dollar will increase in value, we may again see the Canadian dollar be close to par with the US dollar, if this happens gold will soar. Having said that, the world has changed significantly and with the instant communications we have today and the ability of all G8 countries to know what the other is doing, we may beat this world economic crisis faster than anyone would think, so hold on tight. Its going to be a wild ride!