The closer they are to you though, the more of "you" they need, in order to feel that sense of commitment. It's very simple in its principles, not always as easy as it looks, yet farther reaching than you can ever imagine.

To make yourself "present" to someone, you have to bring yourself into the present moment fully, and remove all distractions so you can focus on being with that other person. Here are some hints to help you get there:

Maintain eye contact
When someone is talking to you, they can see where your focus is in your eyes. Looking away means your mind is there too. Looking them in the eye connects you.**

Listen
Don't pay any attention to that voice that's competing inside your head. Be silent, and really take in what they other person is saying.

Acknowledge what they said
"Uh huh... Yeah… Uh huh," is not acknowledgement. Make sure you let them know that you don't just hear what they say, you understand it too. Even paraphrase it in your own words and say it back, or ask them a question that furthers the conversation along.

Add to their conversation not your own
Your experience can be invaluable to them, but not if it's going off in some self-centered tangent. Make sure what you have to say is relevant, or else (again) they'll realize you weren't really paying attention.

Don't judge their viewpoint
This can be a tough one, because in order for you to understand them, you have to filter it through your own set of beliefs. You just have to keep your values to yourself, and not prejudge what you're hearing.

Forget your past
The mind is a funny thing most of the time. They'll say one thing and you'll be catapulted back to High School or Summer Camp and completely leave the present behind. If you get into those moments, get back to the Present. You'll get there by looking at the person with you and listening,

Don't anticipate your future
We also like to race ahead, way too often. Even if our intention is to hurry up and get to the answer, racing too far ahead will leave the solution behind. Besides, the person you're with might veer off at any moment, leaving you once again, not paying attention.

Give them your time
Don't rush things. Time is your life. The other person knows you value your time, so when you give of your time, you give of yourself. They get your present when you give a whole bunch of your present moments.

** Be aware that eye contact varies in different cultures… and the connection that comes from it might be construed as disrespect. Stay within the boundaries of comfort here, or else you'll miss all other points.