The best is when you start asking them questions, such as... "What's your name?" "Where do you live?" "How old are you?" "How much do you get paid?" "What do you do with the money?" "Do you have an imaginary friend?" "What's his name?" and so on... if they refuse to answer a question, "You sure aren't very friendly; I don't believe I want to talk to you anymore." (hangs up)