Just about everyone in the country is grumbling about high fuel prices, but few more so than the airlines. Delta lost $6.4 billion in the first quarter and Northwest lost $4.1 billion, according to reports they released today. Both airlines pointed to the cost of fuel as the major culprit. Delta, for example, said it has experienced a $585 million year-over-year increase in fuel costs. The really bad news for travelers is that Delta CEO Richard Anderson says airlines need to hike fares by 15 to 20 percent to keep up with the high fuel prices.