<p>Well my interview went on for like 2 hours, but the lady was really nice, it was pretty relaxed just a conversation where I explained to her all the things i'd been up to ... she seemed to really like me and said that I was one of the best students she's seen in years and that i'm a great candidate and what not. But I still didn't get in (waitlisted) so i'm not really sure if the interview counts for that much.</p>
<p>I went to my interview straight from school and brought a resume (as requested by my interviewer). She basically just went down my resume and asked me to explain everything on it, so it wasn't difficult at all. It probably took 30-35 minutes. Smile a lot, be enthusiastic (and articulate of course), and ask your interviewer about his/her Harvard experience or job. Shake hands well. Maybe google your interviewer so you can recognize him/her. Not that I did that or anything...</p>