I had a gentleman approach me a couple of nights ago as I was getting out of my car to go into my apartment. He introduced himself and asked if I could give him 90 cents so he would have enough to buy a beer. He was very personable and I gave him a dollar. He promised to do good for someone else when he got the chance; this was his comment through no prompting from me.
Now, it was before dark (I'm a woman and live alone, ya know) and it was right in public view (there were other people in the parking lot) and I live on the next street over from the police station so I took a chance and met a pretty interesting person for my troubles. Had the situation been different I might just have said "sorry" and gone inside. It's really about the vibe I get from the person.