It's kind of a mixed bag for me. I do try to give once in a while, unless I'm in a bad mood for whatever reason at the time, or I simply don't have much/any money on me (I largely use debit/credit cards now, but carry a small amount of cash for those times when making small purchases).
I sometimes feel guilty for not helping though, particularly if I could have, but chose not to (so much for giving to those who ask, bleh

), but on the other hand, sometimes I wonder, "are they really going to use my money to buy food to eat, or are they just going to waste it on drugs/alcohol/cigarettes?"
Maybe I should volunteer more in soup kitchens, that way I can help the poor without just throwing money at them (not like that solves the problem anyway).
Jam it back in, in the dark.