I don't do it often but I'll give street beggars some money here and there but only when they are being honest. Don't tell me you are fucking hungry, I mean you probably are but that's not why you want my money. I'm more inclined to give you a buck or two if you tell me you are a few dollars short of a six pack or something.
That said it's not like these people are in the majority. Most of the bums around my work begging couldn't even tell you what year it is lol.