Facebook has a new feature that lets users synchronize Facebook contact information -- including profile pictures -- with their cell phone address books. Many higher-quality phones, including the iPhone, show your picture on the screen when you call.

What that means is that your Facebook profile picture could be displayed on the other person's phone during important business meetings or other situations where an inappropriate photo would embarrass the person you're calling.

Understand that because of Facebook's new feature, your picture can and probably will be seen beyond your Facebook friend list and in situations you cannot predict. Keep your profile picture tasteful and appropriate to all situations.

These are specific new rules of etiquette that I think we should all observe.

Cell phones seem to make everyone ruder. But it doesn't have to be that way. By following the new rules of cell phone etiquette, we can enjoy the awesome power, convenience and fun of the latest smartphones without making other people feel bad.