iday

I need an honest opinion from you.
I am a doctor (MBBS) by profession with 4+ yrs of work-ex by fall 2010 and aspire to do MBA from one of the top 15 B-schools in US.
My GMAT Score is 720 [V35, Q51]
AWA 3.5
Almost all of the 3 yrs of my work-ex [till now] are in a small town clinic in bihar. I do have some community service under my belt too, both during my college days and working days: namely tsunami fund raising and flood relief during surat floods during my college days.
My college acads are a little below average to be honest and my college is a govt medical college, virtually unknown to the US adcom.
Can u please tell me what are my chances in H/S/W (Harvard/stan/wharton) for fall 2010 or at chicagoGSB?
Also please suggest some realistic and safe B-Schools options for me, considering my profile. Also any word of caution wud be highly appreciated.
regarding improving my profile for the 1 year i have...Shud I join a corporate hospital in a big city like delhi etc....or anything else u suggest?