Yup, guess I'm a glutton for punishment. No, really, I think if you have anything at all that will add to the diversity of their class (and not just in the multicultural sense) that's not covered in your personal statement, then it's best to say it now. No sense waiting for an interview -- you might not get the interview without that crucial bit of information. But what do I know? I don't have any interviews at all (took the August MCAT and only got verified two weeks ago).