Most airlines tried raising fares last week, but they didn't stick because US Airways wouldn't play ball. This week, "American, United, Continental and US Airways raised prices Monday by $20 to $60 per round trip on some tickets favored by business travelers." That's according to the Associated Press. Oil prices are the culprit, not to mention the fear of energy prices going substantially higher due to the unrest in Egypt and Libya. Get the deep background from Flightglobal.