Gasoline prices jumped nearly 10 cents a gallon in the last week, and forecasters say that drivers could see even higher prices as summer approaches. Prices typically rise in anticipation of the summer driving season, but in 2004, it was mid-May before prices topped the $2 mark. This year, $2-a-gallon gas is but a distant reflection in the rearview mirror; it's $3 a gallon we seem to be closing in on.