Go to mdapplicants.com and under the search profiles area, where the GPA box is, enter 3.0 for "under," and you will get a list of peoples' stats. Here are some examples I've just found:
01611 Boston University,
39 MCAT, 2.85 GPA, applied 2004
02112 Carnegie Mellon University, 40 MCAT, 2.92 GPA, applied 2005
03570 Cornell University, 37 MCAT, 2.96 GPA, applied 2006
01992 Harvard University, 39 MCAT, 2.95 GPA, applied 2005
00115 MIT, 37 MCAT, 2.78 GPA, applied 2002
01111 UC Berkeley, 40 MCAT, 3.00 GPA, applied 2004
02258 UC Berkeley, 36 MCAT, 2.90 GPA, applied 2005
01738 UC Berkeley, 37 MCAT, 2.49 GPA, applied 2000
As you can see, these kids all went to very prestigous undergrad institutions; I'd imagine going to MIT and getting a 2.78 still takes a lot of work. On top of that, they all have very high MCAT scores. On top of that, some of them have advanced degrees. Even so, they still only get a couple of acceptances.
There are some profiles that have <3.0 GPA and an average/low MCAT score, but they seem to have master's/SMPs AND are URM, from what I've seen. So it is definitely possible to get past a screen with a sub-3.0 GPA, apparently. I don't know if the screen accounts for undergrad reputation, though.
For example, maybe the computer program is told only to allow sub-3.0 applications through if you went to a university that they classify as top-15 (Harvard, Yale, Columbia, MIT, Berkeley, etc. etc.). Even so, it's obviously a long shot.
Long story short, if you have some money you don't mind parting with, take a chance. I'm not going to tell you not to apply, because you never know what could happen. Realistically, though, if you don't get a high MCAT (like over 35), then you probably don't have much of a chance. If I were you, I'd take some undergrad courses just to hit that 3.0, and then do an SMP. Good luck.