Face the speaker and maintain eye contact.
Talking to someone while they scan the room, study a computer screen, or gaze out the window is like trying to hit a moving target. How much of the person's divided attention you are actually getting? Fifty percent? Five percent? If the person were your child you might demand, "Look at me when I'm talking to you," but that's not the sort of thing we say to a lover, friend or colleague.
In most Western cultures, eye contact is considered a basic ingredient of effective communication. When we talk, we look each other in the eye. That doesn't mean that you can't carry on a conversation from across the room, or from another room, but if the conversation continues for any length of time, you (or the other person) will get up and move. The desire for better communication pulls you together.
