I would like to take a moment to stress the importance of common courtesy. Today I had the joy *insert sarcastic tone here* of experiencing a few of the many who have clearly never been instructed in any area of politeness.
Please be sure to treat those who work in fields of customer service with the decency you would expect to be treated with. There is a difference between service and servant. Just because we have to keep quiet due to the desire to keep a job does not mean we get to be your verbal punching bag.
If you happen to need lessons on proper public etiquette, eHow can teach you.