You meet a homeless person on the street. Do you give them money? Why?

I was looking for a journal prompt and this was one that jumped out at me.  I am curious to know all of your thoughts on the subject.  Me, personally, I usually don't give money to the person on the street.  However, I do donate to homeless shelters, battered women shelters and food banks.  I believe that by donating to these organizations that have the tools to provide help for the homeless that I am doing more good than simply giving the homeless person money.  I have heard of people walking the homeless person with them to get something to eat, but I am just too shy and I have never done this.
Those are my thoughts. . . . what are yours?