Bottom line: We were paying $4.50 per gallon due to nothing more than speculators and investors.
In late 2004 world oil production stalled @ around 86 million +/- 500K barrels a day until july-aug 08. During that time China/India increased consumption by around 8 million barrels a day. I think it was a little more than investors.
If you look back to spring when the food riots broke out around the world you can see where the oil was taken from. Oil is food in the modern world.