I believe around 10 years ago, the price per gallon of gas was around $4. It's now around $2.50, so we have dealt with prices that high in the recent past.
Hurricane Ike put most of the oil processing plants in the Houston area offline, which led to a US-wide spike in gas prices. I've been there when it happened and it wasn't pretty.
I'm not implying a correlation--there is one, along with a very longstanding correlation between oil consumption and GDP. What I'm implying is the much more contentious claim that this relationship has a strong causal component, too.
Good old-fashioned fraud. Oil prices had nothing to do with it.
Source: acquaintance who spent three years in court testifying about the rampant fraud in the mortgage industry. He worked for an investment bank which is no longer with us.
I'm well aware of the structural fraud.
My point is that the reason that the bubble popped at that point (and not some years later) were the skyrocketing oil prices, themselves a consequence of (conventional) peak oil.
But I guess that it's a bit academical, as that bubble would have popped soon enough anyway...