I really shouldn't be participating in these discussions, since I have nearly 500 people on forum block, so I'm only hearing at most half the of chatter, but I have to add one thing...
I always hear about how there's tons more oil out there than people think. Either it's known and not discussed, or it's "secret" in the back pocket of an oil company or oil state.
I accept ALL these arguments about additional oil. All of them. Public. Secret. Real. Unreal. Planetary and extra planetary. No argument.
Even with that as a base for discussion, there still remains the issue of economics. Any discussion of the economics of oil is pointless if you exclude economics (and just focus on geology). The point is that for all the oil out there, known and unknown, there's also an associated cost to extract it.
The Athabasca oil sands weren't economically viable until 2006/2007 price levels, even tho they've been a known quantity since the early 1700s. Only at $80+ per barrel at the well head did started people talking about a "second Saudi Arabia." All fine and good, except for the basic economics of price elasticity. Those same well prices resulted in California formulated gas that was hitting $5 per gallon.
Previous economists' estimates of the price elasticity of gas had predicted a price of $7/gal to shift US consumer auto spending habits away from their SUV guzzlers. Turns out that estimate was high. It was actually around $4. The SUV market collapsed, along with Ford, GM, and Chrysler. This shift toward more efficient vehicles in turn created downward pressure on prices (i.e. reduced demand). This balance between supply and demand and the equilibrium price that keeps them in balance is fundamental to the discussion. It's not just the existence of oil. It's the price at which it can be extracted, the resulting price at the pump, and that price's effect on the supply / demand equilibrium.
Saying there's a ton of supply without factoring the price of extraction and the effects of that price on production is just as fallible as people running around talking about the imminent collapse of society when the supply of oil "runs out."
This relationship between supply, cost of extraction, and the resulting level of production is what Marion King Hubbert was modeling back in 1956 and he created a model that, again, has been proven over and over to be accurate in predicting oil production. He never ever said oil would "run out". He did create a very successful model that predicted production, however.
Again, just to be explicit: Peak Oil doesn't say anything about oil reserves -- it predicts oil PRODUCTION -- this is something very different from reserves.