Hey, I'm a PhD student at BU right now, and there they don't let you start the MD program until you finish your PhD. I realised that I wanted to do medicine a year into my PhD, and now I am taking the MCAT in April and applying for 2004. I believe that if you are accepted to medical schools but haven't defended yet, you are allowed to defer one year in order to complete your defense. That's a pain, though... If anyone wants any more info, I'd be glad to help.