Responding again specifically to @CAEngineer, I entirely agree and within a matter of 2 weeks turned down the offers of admission from all schools I was no longer considering. The only six schools I have not turned down are MIT, Caltech, Yale, Stanford, Harvey Mudd, and Princeton (I am also on the Harvard waitlist). It is disrespectful to sit on an admission offer you know you will not take, but it will not jeopardize the admission of other students simply because they are from your high school in the future.