You pass a co-worker in the hallway and he asks, "How are you?". You respond by:

Telling him that your back has been hurting you and you have a cold

Explaining that you are tired and stressed out in your job

A co worker comes to your office to introduce you to a friend of hers. You:

Stand up, establish eye contact, smile and shake his hand

Wave and tell him how happy you are to her

When breaking the ice with a contact at the beginning of a meeting it is appropriate to discuss such things as the weather, politics and traffic

A co-worker shares office gossip with you. You:

Thank him for telling you and pass the stories on

Check out the facts with other employees 

Politely listen and keep the information to yourself 

It is acceptable to leave on your personal cellular phone during office hours and answer when it rings