I genuinely think it should be a requirement that people work in food service of some type (wait staff, fast food - whatever as long as they deal with customers beyond "welcome to ___ ") for a minimum of one summer.

I think that it would be a shock to be on the receiving end of demanding, rude and insensitive people and have to smile and apologize for things that are not your fault. I think we'd be able to return to the courtesy as the rule, rather than the exception, culture. :P