Wow, guys, I think the OP got the message!
Yes, it is probably not the brightest idea to turn down your only acceptance, but I think this is a valid question. I was curious myself, not because I want to turn a school down, but just in general, if this is something people do...
As somewhat of an anecdote, There is a girl now in Harvard who turned down Tufts before reapplying... From her blog (which you guys must know), she said Tufts didn't even look back at her the second time around. So my only addition to this discussion is, certainly, if you were to do this, don't imagine the school you turned down will even bother with you again...
As a matter of common sense, it also seems that doing this should raise a humongous red flag. Why did you turn down the school? how strong are your motivations for medicine? How did you not have the foresight to avoid a school you're not interested in? How gullible are you? None of this is meant to reflect on the OP, I'm just saying that these might be reasonable questions AdComs must come across when reading an app from someone that turned down an acceptance for something other than an extremely persuasive reason...