I arrived and got my security badge. My point of contact escorted me to an office, where he set up a conference call to the first person I was supposed to be interviewing. This person ended up being too busy to talk, so I talked with the team lead. It was a pretty standard interview, he asked about the projects I listed on my resume and my experience. He answered the questions I had. I felt like I was qualified for the job as he described it and that it would be a good match for me, so I left feeling positive. I was told that they would reschedule an appointment for me to talk with the first person. I wasn't worried, because I had done so well at the interview, however when I called a week later, the position had been filled.
I guess my only advice would be to call back 2-3 days after the interview, even if you feel you did really well.