The futility of President Bush's visit to Saudi Arabia on Friday has been underscored by a new benchmark: $4 for a gallon of gasoline.

The Lundberg Survey tallied 7,000 retail gasoline prices around the nation last week and found an average price of $3.79, up 17 cents in the last two weeks. In Chicago and on Long Island, prices reached $4 a gallon for the first time.

And $4 could soon be the national average, she said. Gas consumption typically increases significantly after Memorial Day.

"The refinery margin on gasoline is so poor, I think the upward pressure on the refining margin will push up the price at the pump, even if crude oil does not," she told Reuters.

Crude-oil prices continue to climb today, approaching $128 a barrel.

On Friday, President Bush asked the Saudis to produce more oil. The Saudis say they have been pumping 300,000 barrels more a day in response to demand from buyers since early May, but that increase is not expected to have any impact on prices.

Here is a snapshot of gasoline prices in some other markets, from CNN:

•    Tucson, Arizona: $3.48 a gallon
•    Denver, Colorado: $3.64
•    Houston, Texas: $3.65
•    Minneapolis, Minnesota: $3.71
•    Portland, Oregon: $3.77
•    Atlanta, Georgia: $3.78
•    Washington, D.C.: $3.82
•    Hartford, Connecticut: $3.98
•    San Francisco, California: $3.98