After half a year of dealing with the freshman admissions process, it was finally time for me to respond to the few institutions that had accepted me either directly or off of their waiting list. Maybe it was the wierd mix of caffeine, final exams, and anxiety-induced insomnia, or maybe it was just the cynicism I had built up from enduring the game of exaggeration and self-embellishment... but it was time to have a little fun. Trust me, if I thought that they would actually read it, I'd have written an essay.

Dear Mr. [Doe]:
Thank you again for the offer of admission into the Mellon College of Science. Unfortunately, it is with deepest regret that I must inform you that I cannot accept your offer to attend Carnegie Mellon University.
Please understand that this is in no way a decision based on the quality of your institution, but rather it is indicative of the exceptional quality of the institutions that have already accepted me. I appreciate the time and effort that you and your colleagues have put into the application review process. Your institution is exceptionally gifted, and I welcome you to review my application again next year should I decide to apply for transfer after my freshman year.
Sincerely,
[me]

Repeat as necessary for the other schools. Oh well, you had to be there.