Im a social entrepreneur currently involved with non profits doing exactly what you are talking about. Theres actually endless ideas for this so the challenge isnt which idea the challenge is to decide that you really want to do it.

Personally i decided it was worth it and now have more projects then i can handle all or most of which are focused on helping a larger group of people through services related to education and health and other "cause" oriented topics.

If you want to talk more send me an email. And if you want to help out with any of the projects let me know as well.