That's when I say, "Sorry dude, I don't have anything but the local police are always willing to lend a hand to a citizen in need - I'll call them and we can wait for them together to make sure you get back home safe." I always get a kick out of that because it's hilarious to see those people start backpedaling as quick as they do. Then I press more, "No, really I insist... I want to make sure you get home alright since you don't have any gas or money" I really just make a fake call to whomever and start telling the story on the phone, "yea, hi, there is a gentleman at ______ who ran out of gas and doesn't have any money to get home, I was hoping you could send an officer out to help this guy get home..." About then is when they and walk/run away.