Cell Phone Etiquette

I think cell phone etiquette is really important for people to be aware of and practice. In so many places, talking on your phone too loudly or at inappropriate times is just plain rude and people take a lot of offense to it. One thing I found on Wikipedia is that many places are installing signal jamming equipment to prevent cell phone use (illegal in the US) or some newer buildings, such as auditoriums, have installed wire mesh in the walls which prevents signal penetration that does not violate signal jamming law. Also, places such as doctor's offices, movie theaters and libraries prohibit the use of cell phones in their buildings.