Texas Tech (Lubbock) offers a 3 year M.D., but only if you want to go into Family Medicne. It is called the FMAT program. Essentially, it condenses your clinical years, but requires you to enter into a family medicine residency at Tech. I believe that 2 years are covered on scholarship... It might just be one though. Regardless, if family medicine is what you want, this would be the cheapest/fastest way to do it. There is also the option to bail out, and just do a 4 year M.D. anytime during the first year (and second too I think). You would have to look up the details on the website.
Not sure about any other programs.