Yeah, there have been a couple times I've helped the homeless. One time I was out of town somewhere, on the road, and I stopped at the nearest food establishment. Two people were outside McDonalds with a little sign simply reading "any food you can spare." Well, I had just gotten a 2 for $2 something and a salad. I gave them one of my sandwiches and the croutons from my salad. They were happy and very appreciate.
My stance on helping homeless is this..you have good intentions in giving them money. What they do later is on their conscience...not yours.
...And you're all going to love this link.
http://freegan.info/
-oddguy