You don't need to look far to find someone who is hungry; sure many people on this orange site may not be hungry of food but I bet there are many who starved of love. It really doesn't take much to offer an ear to someone in this lonely day and age.
Perhaps it's part of my religious background but I personally find that if the foundation of one's life is based on material things, then one is in a constant state of unhappiness. I come from a country that is considered poor but Western standards, however looking back I realize that the West is wealthy yet poor at the same time. Most are just busy worshiping money, sex, status or power. It's like we forgot about our humanity.
So yes, you may not be able to change _the_ world but you can change _one_ world at a time.