I interviewed for 2 hours 20 minutes at UPitt. A retired Doc basically sat there and told me about the world of medicine, what it takes to be a good doc, by the end of the interview he was telling me how to plan my retirement (because he retired with 7 million dollars in the bank) and showing me his family pictures. This guy was actually really inspiring and is by far my most memorable interviewer I had.
I ended up missing my next meeting with the admissions dean. When i showed up and told her I was late because my interview was so long, she said "who was your interviewer?" When i told her who it was, she immediately smiled and said "you probably should go have a beer or something, every time I have a conversation with him I feel like I need a beer afterwards, he's so intense."
Basically, i got a 2+ hour motivational speech on how to go about my career, and some of the best advice I have gotten thus far (this was 2 years ago).