I have to tip my hat to United for their customer service system. My travel agent (American Express) screwed up my seat assignments and I had to call United to get them fixed. I called United's customer support number and after picking up, an automated voice immediately said, "Is this Preston or somebody calling on behalf of Preston?" Obviously they've added some sort of caller ID capability to their system. It was great. Within 15 seconds I was speaking with a customer service representative without having to punch in any personal information. Great job, United! This is how it should be done.