hm2009, I'm with you in many ways. Want to get into social enterprise from banking. GPA of 3.5, GMAT of 680 but like you, a compelling story, lots of service, overseas entrepreneureal expereinces etc. etc.
I am beginning to think those stats are what's keeping us out, because as compelling as our stories are, and as significant as our accomplishments may be, there are plenty out with there who did the same and more, but who had 740's and 3.70's.
I'm quitting my 8am-8pm banking job if I don't get into school. Will start following my passion and maybe end up living in car but one thing I've learned through this is that nothing (short of 7 figures) is worth staying at a job you hate.
Best of luck to you, hope we all get in.