At $600 we will be switching to walking, maybe bicycling, electric bicycles are way into the cool zone btw, great ones cost $2 grand, but they would be selling if oil was that high...
There is a company that makes diesel out of ALgae. When Oil was 140 they got alot of attention so at 600 they would be king of the road. Either way at 600 we would all telecommute and ride horses. By the time you got to work your ass would really be hurting. Not to mention the parking lot would probably reak of Horse SHIT....