Honestly, if you are on the wait list, to me this is a now or never sort of deal. I remember applying to pharm schools and I told God, 'just get me in one. I will give my right arm. I will, I promise!' I was desperate. I wanted it more than anything.
If you feel the same way, I say call the dean of admissions and let him know how happy you are to be on the waiting list and express your sincere interest in their program, how special it is, how it is better than any other school, and how you look forward to hearing from them. What's the worst that can happen? You get embarrassed, you remain on the wait list. The best? He likes you and remembers your name when they need to pull someone off...
(this is assuming it's a generalized wait list and not numbered by rank of who they would admit)