This graph of the history of the price of oil shows a long-term price decrease amid progressive speculative bubbles from the mid-19th century to just before the turn of the century.  During this time, extraction was streamlined and consolidated, and there was a large increase in demand due to new oil-dependent, pervasive technologies such as the automobile. 

From the early 19th century until the 1973 oil shocks, the price of oil remained relatively stable as shortages were considered a non-risk and the externality of emissions remained undiscovered.  From 1973, the OPEC cartel began heavily interfering in the market.  OPEC recognized that oil had pervaded much of the economy and, as such, it was an inelestic good: this meant that even at a very high price, people would continue purchasing oil. 

Countries such as Japan, Korea, and France interpreted this development as a sign to get out of oil, that is, to harness nuclear, thermal, wind, and other forms of energy for what they could and minimize dependence on foreign oil.  These countries now consume less oil than they did in 1973.  These countries also began producing more fuel-efficient automobiles, which have gradually come to replace the muscle-car paradigm of the pre-OPEC world.  However, in the US the effect of policy was to ride high oil prices for as much gain as possible.

Nevertheless, the recent long-run rise in the price of oil is probably less due to the nature of the market, OPEC, and the activities of speculators and more due to the increasing scarcity of proven oil reserves. (Although, ironically, rising global temperatures and improvements in technology have made discovery and drilling in the Arctic more feasible.)

This is a graph of proven oil reserves. Note it's shape is the near-inverse of the graph of oil price.    

In the September-October edition of Foreign Affairs, Edward L. Morse argues in "Low and Behold" that the price of oil will remain low for the foreseeable future, for both economic and political reasons:

Now that Saudi Arabia has a huge spare production capacity and thus the tools to advance Washington's economic and political goals, it should be easier to establish between the two governments better and higher-level communications about the oil market and the global political economy.  Such a dialogue cannot take place at the level of energy ministers.  It requires the kind of political attention that can come only from the Department of State or the White House.  Saudi Arabia appears to want to keep oil prices between $40 and $75 a barrel in order to promote global economic growth and limit the revenues of rival producers while nonetheless adequately funding its own budget.  Washington's relations with Riyadh involve other difficult diplomatic issues, such as the creation of a Palestinian state and how to secure participatory governance in Iraq after the withdrawal of US troops.  With its spare production capacity, which is unlikely to disappear anytime soon, Riyadh has earned itself special standing with Washington.  Neither China nor any other country can do as much as Saudi Arabia can to bring change to the global energy sector.  Thus, aggressively seeking to end oil imports to the United States from the Middle East - a policy articulated by Obama during and after his election campaign - is not the way to harvest the potential fruits of US-Saudi relations. 

It's true that the United States needs the assistance of Saudi Arabia to both fight its Middle Eastern wars and broker peace in Palestine.  However, precisely because of this, it is in Saudi Arabia's interests to prevent Middle East peace from ever happening and assure it remains of political use to the United States, thereby giving it leverage to determine the price of oil.  Were the United States to develop more nuclear power, as John McCain has proposed, or begin developing other forms of energy, Saudi Arabia would still insist on the US's purchasing its oil if it wanted continuing diplomatic assistance in the Middle East and a low oil price. 

Nevertheless, this begs the question, couldn't we possibly kill two birds with one stone by doing what France, Korea, and Japan did and reducing our oil consumption?  This would insure the US from the price shocks that will accompany inevitable shortages to come and reduce Saudi Arabia's incentive to be an obstacle to Middle East Peace.