The lack of context for phones frustrates me because it means you can be "accidentally invasive." If you approach someone in real life, you can use your senses to gauge what they're doing, thinking, and feeling at the moment of contact, and make an social gesture that is appropriate. It helps with first impressions, which are always important. And with email the asychronity is high so your risk of reaching someone at a bad time is low, so again, you can make a good first impression.<p>But if you're going over phone, there is some expectation of real-time availability - nobody really likes voice mail. Phone calls have a dreadful suddenness to them. Thank goodness we're moving past the days when almost everything had to be done by cold-calling a number.<p>IM and texting can be even worse in some ways as the expectations of timeliness are fluid so communication may get frustrating when one person is moving way faster than the other, but I think they actually work really well when used for short-term "business update" types of communication: "I will meet you at 5pm." "Do you have a link for &#60;x&#62;?" "We changed our plans for the meeting." etc.