I've written about oil prices and world supplies on my blog in the past*, and I found the following information rather interesting. This also comes from the current issue of The Economist.
The world had 1.2 trillion barrels of proven oil reserves at the end of 2005, according to BP. If overall production continues at last year's rate, known oil will last for 41 years. But it will run out more slowly in some countries than in others. At today's extraction rate, Saudi Arabia's reserves, which account for more than a fifth of the world total, will last for 66 years.
As you can see, at last year's production level, the remaining oil that is currently known to exist within U.S. borders will be completely pumped dry in 12 years - 2018. Mexico's reserves will be gone in 10 years (2016).
So, bought that electric car yet?
* See Oil: America's Smack and, more recently, How Much Oil Does America Import?