I will try to be generous when I can and if I feel it appropriate. But, I once had a guy approach me in my truck at a drive thru asking for money for something to eat. I told him if he would tell me what he wanted I would gladly purchase it for him with my order. Told me i didn't need to do that if I just had a buck or two to spare. I told him I would be glad to buy him something and then he told me he was just gonna be honest that he wanted a drink. I told him i would feed him but I would not feed his addiction.
I've mentioned this here before, but I'll mention it again.
KOCO (OKC metro news channel 5 (ABC)) did a report a few years ago on Oklahoma panhandlers.
Some organization created a coupon booklet (with bus passes, food vouchers, and tons of other stuff in it) and tried handing them out to offramp and intersection panhandlers.
My statistics memories are a bit faded on this subject, so I'm just going to throw out numbers as an example, but it was something like only 50% of the beggars accepted the coupon books and of those handed out, less than 10% of the coupons were redeemed. It was a hugely significant number like that. After that story, I went from giving a buck or two out to almost anybody that asked for it to not giving out a single dime to beggars.
I know there are people out there who need financial help, who need a hot meal, but that story spoiled it for the whole bunch.
I do, however, donate through Kiva.org. So I try not to be too stingy with my money.