I too was faced the same dilemma a few years back and on a whim I joined a small volunteer organization that teaches street children. Being a one trick pony I decided to teach them computers. In just 2 months those kids, who did not know the English alphabet learned to use MS-Paint doing stuff like Undo/Redo/Copy/Paste, etc. Seeing those kids learn was one of the happiest feelings of my life. I later heard that one of the girls got admission in a govt. school because of what she learnt in that org.
Anyway, the reason I say this is because I read an article a few months back (will link it if I can find it) about how in Western societies there is a very strong emphasis on giving back to the country. Even people who are doing well generally volunteer on weekends for community service, etc. They have a very strong feeling of patriotism and an in built societal structure that makes them want to give back.
Now I have never lived outside of India so I cannot say if the above is true or not but having lived in India all my life I have never seen anyone, any relative, friend, etc do any sort of community service ever (unless of course there is religious angle). So all in all we have a lot of people complaining but very few doing anything.
I think every person who has completed college has the ability to make a difference but because the problem seems to be so "huge" nobody wants to do anything about it or is maybe waiting for others to lead them the way. The thing is you don't have to change everything, you only have to realize that anything you do no matter how big or small still makes a difference.