ugh. United cancelled my flight and rescheduled me for one 5 hours later. I asked the United employee about getting on an earlier flight, and she insisted that they were full. I then pointed out that the people in front of me got on that flight, and she conceded that people with United Premier and Mileage Plus got priority (United had screwed up my frequent flier info). My response was, "Oh, I get it. It's not full, it's 'full.'"

BTW - when United cancels your flight and bumps you five hours, you don't get any compensation.