Can you spare some change

I have been working in the city for nearly a year now. I have gotten used to most things that I experience every day. I have mastered the subway. I can reach into my handbag, get out my Metrocard and swipe it without slowing my step. I know which end of the train to be on for optimum efficiency. I time the lights while I walk and carry my umbrella every day. I glare at the cars trying to make right turns into the crosswalk. But I don't know what to do when someone on the subway car starts to preach or sing or address me and my fellow passengers. There are often blessings and thanks and then he (its always been a man) walks through the car asking for money. I never give anything. I always feel badly. I have seen signs on the subway saying not to give money to panhandlers, rather to donate to a charity. I think this makes sense. But to see some who looks to be in need and refuse... This happened again on Tuesday evening. A man reciting something like a poem, full of blessings and prayers for our soldiers in Iraq. When he walked past, I looked down. Two men did give some change. One a man in dusty work shoes. Another a young man, in casual clothes. It seemed to me the the ones with the least were the ones who gave. And I still don't know what I will do when it happens again. Should I put some change in my bag or keep looking down?