Hey everyone,
As a waitlisted person last year, I thought I would offer some advice. First, some info about me. I graduated from Yale with a sci/non-sci double major, good grades, good MCATs. When I got the interview invitation to Vanderbilt, it was the week of Sept 11, and I really wasn't in the mood to make a flight reservation from the Northeast, so I decided to take advantage of their regional interview option. As I was later told by my pre-med advisor, this was a big mistake. Anyway, I was eventually waitlisted at Vanderbilt (my number two school).
The day after commencement, I left for a month-long trip to Africa, after which I was home for 2 days. I then left for a three week road trip with college friends. By the time I made it home, it was late July, and there was no word from Vanderbilt. I called their admissions office to ask what the deal was with the waitlist. After I gave the secretary my name, she sounded surprised. She told me that I would have been accepted in June, if I had been in contact with them during May/June (when I was traveling/worrying about graduation events). I told her I was still very interested in Vanderbilt, and she told me she put my name back on the top of the list (their list is ranked, by the way). She assured me that a spot was expected to open within that week. I called them every week until I arrived at my current med school. The person who was supposed to give me my spot never left.
Long story short, it is definitely possible to get off the waitlist, but you have to let them know you are interested.