Quake3World

Oil isn't going to actually run out. The theory is that once you hit the production peak, demand continues to outpace supply further and further, and prices are only going to go up. At some point -- not too far away according to the research -- the oil will be too expensive for the average consumer to buy. That's when things will have to start changing.
It's not really a doomsday scenario, it's just simple cause and effect at that point. If things haven't changed by then to allow for a transition, then things will be forced to change to make up for the drastic lifestyle difference. That's all Peak Oil is about.

And Hubbert was one of the guys who originally thought up the model -- it's called Hubbert's Peak -- back in the 70's. If I recall correctly, he predicted that peak would be reached in around 40 years. From the research I've read, things are still pretty much on that track, give or take a few years.

edit: 40 years from his observations in the early 70's that is.