$100/gallon gas would do a lot more than slow down commuting. It would make air travel prohibitively expensive (thousands or tens of thousands to fly anywhere - fuel is already the biggest cost at any airline with $100/barrel oil). Shipping would also be seriously impacted; the 20% savings on a radio made in China would be offset by transportation costs. $4 winter strawberries from Chile would be no more. That, and global recession. Personally, sounds to me like some good and some bad.