Mobile phone etiquette 1

Mobile phones have become a necessary evil these days. It is extremely hard to imagine a world without these gadgets and sometimes I wonder what people used to do to communicate when these phones were not available. While conveniance is one thing, annoyance is the other side of the mobile phone. I have been both the victim and culprit of not following the basic etiquettes demanded while using a cell phone. What can we do to use the mobile phones more appropriately and socially?
1. Use better sense and discretion while using a mobile phone. If speech is silver then silence is golden!
2. Its always impolite to banter on the cell phone in public places where people need silence: the library, places of worship, movie halls, classrooms, boardrooms!