Oil prices appear headed back toward $70 a barrel, a level not seen since Hurricane Katrina battered the Gulf Coast, and sporadic shortages have raised gasoline prices in the United States. While last summer's price spike triggered outrage in Congress and hurt sport utility vehicle sales, it caused only a hiccup in motor-fuel consumption. And for now, with demand back on the rise, the economy seems capable of absorbing uncomfortably high prices. Analysts warn, however, that consumers and businesses could be just one major supply disruption away from more serious financial consequences. Sherry Cooper, chief economist at BMO Nesbitt Burns, said the ramifications of $70 oil and $3 -a-gallon (65 euro-cents-a liter) gasoline would be "more mild" the second time around "because we're getting kind of used to it."