SUNY Upstate has an early acceptance program that you apply to at the end of sophomore year. There is an SAT cutoff to limit applications. (I think 1300-1350) I believe they get about 125 applications, interview ~50, and then accept 20-25. I believe you can be from any college and apply bc i met people from all over when I interviewed in '04, although I think they may favor some of the Upstate NY schools. If accepted you enter after you graduate college. (you still have to fill out the AMCAS, but you dont have to take the MCAT) Its nonbinding on their part so you are free to apply other places if you feel like in senior year.
I believe SUNY Buffalo has a similar program, but it is binding.