Applied for an interview online, got a response via email within a couple days asking me to come down for an interview in Seattle (no phone screening interview). Amazon was very generous in paying for my flight, hotel, food, and transportation within the city.
The actual interview was an all day programming task in which you solved a problem in a group (no whiteboard coding). I found this to be a really enjoyable process and within only an hour or so of being at Amazon I felt right at home programming my solution to the problem.
This group interview process seems to be a real winner to me, as it felt a lot more natural to actually get to write code on a computer (multiple choices of programming languages and IDEs) and have access to the internet and teammates for help. I feel lucky I managed to get this type of interview - I had a very positive experience.