OK people...a lot of the folks you see begging (although here I've never seen it at exit ramps, usually in front of convenience stores) are homeless, and a lot of the homeless are mentally ill and/or alcoholics or addicts. I work in the social service field in our county, so I'm somewhat familiar with these situations. If I see someone begging as I'm going into the store - on the way out I give them a sandwich and a drink. NOT the cash. I have also engaged some in conversation, and told them places they can go for help. If you really want to help someone - there are ways of doing it short of giving them the opportunity to get their next fix.
I agree Cookie... I have worked in the psychiatric and forensic psychiatric hospitals in my province and the best thing to do is to make eye contact, smile and engage them. You will be able to tell pretty quick who is suffering from a mental health issue and who is just begging.... I also agree with the food instead of the cash.
I rarely carry cash these days as in Canada, our 1 and 2 dollars are coins and they get heavy....:)