Basically, it's a geological statement from the 1950s that states something fairly obvious: That after a certain amount of time, the production of an oil field(in terms of barrels a day, which one barrel is 42 gallons) rises, hits a peak/maximum and then hits terminal decline. Thusly, by averaging up all the oil fields in the world, doing some complicated math(made more difficult by some countries witholding production data and reserves numbers) one can guess when the world will reach a maximum production of oil(which is currently at about 84 million barrels a day). Keep this in mind, this isn't when the world runs out of oil, simply when a maximum production is reached.
i just saw the news there... petrol prices in the UK are now 90.2p per gallon. thats a lot - considering when i started driving it was something like 79p. prices are just going up and up :wth: