Whether the gasoline prices and the fallout from Katrina will affect the entire economy was not clear several weeks after the tragedy. But consumers are expecting the impact to be significant. A Harris Interactive poll of 2,242 consumers the second week in September showed that virtually all consumers expect Hurricane Katrina will affect the U.S. economy: A near majority -- 45% -- expect the impact to be great. 41% expect somewhat of an impact and 13% a small impact. Only 1% expect no impact. Whatever impact the hurricane ultimately has on the economy, consumers base their behavior on their expectations and so there is likely to be some impact on the economy.

A survey of 1,622 consumers by Shopzilla/BizRate as prices were cresting showed that 40% of consumers plan to do more Christmas shopping online this year as a way to reduce their spending on gasoline. 15% said they will shop online "a lot more" to avoid burning gasoline going to stores and 25% said "somewhat more." The balance -- 60% -- said their shopping habits will not change.

Rising gasoline prices are the latest in a series of bad news, Baumohl notes. "Rising interest rates, gas prices going up all year, people not saving much money, minimal wage growth and now this, which will lead to higher heating costs this winter -- something has to give," he says. "One of the things that consumers will give up is non-essential driving. They won't be going to shopping malls if there is another option."