I'm applying this summer, too. I need two science professors, one non-science, one research advisor, and a personal reference, preferably from a physician, for my top choice school. I just went back to a couple of my assembly-class professors and was like, "Hi, you don't remember me, but I got an A in your class, here's my transcript and resume, write me a letter?" And they did. They're used to that sort of thing. Good luck with your applications; are you taking the MCAT on Saturday? Gee, I'm so excited I could just scream...