Interesting that people will pay what the owner says they do, when in physical proximity, and totally exploit the creator's friendliness when it comes to "donationware".
Maybe someone running somekind of website where donations are accepted could run this experiment: Put on your sign-up/logout or download page a donate feature, and pictures of you next to your children/pets/dependent whatever, or a picture of your old car/tv and some text saying "I'm looking for money to replace this", etc.
I think physical proximity is a factor, but the emotions involved are more like "I can't screw the guy" and "I should help the guy" or "I should be a good person and do this", so if you can make these feelings emerge...
