Dangling conversations

Why is it people feel the urge to walk around when they use a mobile phone?

Is it the mobile in the name that confuses them? And why do they have to get up from their desk for privacy or to avoid disturbing their colleagues or because they have worms or whataver and stand by your desk bellowing down the phone and pretending you are not there?

Do they know how painful it is to have a phone surgically removed I wonder?