Well I recently had a revelation about this. I think it's ok to call after an interview, although they may not tell you anything, b/c if they knew, they would have told you already! So when I called up BU post-interview, I just said "are you still giving out acceptances?" She told me yes, without me giving her my name. But if you want your info, just ask.
So here's my coincidence/revelation: I have called most of the 18 schools I applied to several times for status checks. Turns out that the 6 interviews I got were from schools that I never called since application completion. Weird, huh? I wonder if it means anything....
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FYI, if anyone is interested, I was thinking about sending a letter to the Dean at U Miami asking for an interview while restating my interest, etc. My uncle who used to interview for Columbia med school told me NOT to do this. So take what you want from that regarding asking for interviews. I still think update letters are good things when on a waitlist, though.
OK, enough rambling for me