I know just the way you feel. I realy have a problem with people who say racist things and a lot of the people I'm surrounded by do. Sometimes I try to argue with them but they can be so stuborn! I get so angry when somebody says bad things about other people when they havn't even tried to understand them first.
I don't know what one can actually do except stand up for your beliefs, and don't just let them get away with saying such things that hurt you too, at least make them a little angry if not embarrased for saying such things about other people who they havn't made the least effort to understand.