As a technology professional for more than 25 years, I am used to family hitting me up everytime I visit, but those who would normally be a client like friends and family of coworkers or businesses or churches seem to think that not just my advice but long hours and work are free as well. Although some often act like they really never knew either how much time it takes or how much your time is really worth - don't believe it. Why do you think they are trying guilt/con you into doing it? If you really want to teach them a lesson they won't forget, when they ask you to dinner only to spring a request for computer help that "will only take you a minute", help them out but insist that they sit and watch you (so they see it never really takes a minute of two) and then spring the statement that as a computer professional, you're sure that they understood you will be sending them your bill in full hours at the going rate of $150.00 per hour and carry through on the promise. You won't have to do that too often.