Another excellent Article in NYtimes for students on the waitlist

http://www.nytimes.com/2010/04/14/education/14waitlist.html?pagewanted=print

A place on the wait list is usually offered to students who have applied for regular admission and it does not, as a rule, mean that the school needs more information about you – it merely means that the school doesn’t have the space to accept you immediately. Basically, the college is waiting to see what its first-choice accepted applicants are going to do – if the school needs to fill slots they will offer you a spot in the freshman class.
Colleges usually rank their wait lists, so you should get in touch with the admissions office and find out about your ranking (the higher you are on the list, the better your chances of being accepted). Ask about the school’s wait list history: how many students have been waitlisted in the past and how many were offered admission. You should also ask what kind of housing and financial aid is available to late-accepted students.
Meanwhile, don’t passively wait out the decision-making process – ask for an interview (whether it would be your first or second) and keep the admissions office updated about academic or extracurricular honors and achievements. It may also be helpful to write to the school and let them know that you will definitely enroll if you’re accepted (but don’t make this claim unless it’s absolutely true). Your high school guidance counselor can also give you advice and support during this process.
If you’ve been waitlisted you will not be notified about admittance until after the May 1 decision deadline has passed, so to be guaranteed of a place in college, you’ll need to accept a spot in a school that has already accepted you. Fill out the paperwork and send in a deposit – if you’re accepted off the waiting list and decide to attend that school, you will forfeit the deposit you’ve already paid. You may not hear from the wait list school until August 1, so attending that school may be a last minute decision. Ultimately, waiting out the wait list can be a stressful and expensive option, so you need to carefully consider how badly you want to attend that particular school. If you’ll be just as happy attending a school that has already accepted you, it may be wise to commit to that school wholeheartedly and get on with the process of preparing for college.