Phone and e-mail are different tools. Each have their place. I wouldn't consider them interchangeable. It also depends massively on the type of job you have, so that blog post works well for the blogger, but everyone's situation is different. I generally prefer e-mail for all the reasons listed.
However, downsides of e-mail:
it is easier to say 'no' to someone by e-mail. People often feel under-pressure to say 'yes' to someone when talking directly. So if I need someone to do something for me, I may ask them by phone as it increases the chances they'll say yes and I'll get what I want.
it is easier to ignore someone by e-mail. People have a natural tendency to respond to whatever is facing them, so if you phone someone you're more likely to get a response straight away, whereas an e-mail may go to the back of their 'to-do' list. So if I want someone to do something for me quickly, or I want a quick answer to a question, I'll normally phone them.
written evidence of a conversation can be damaging. This is particularly true of internal communications in a company, where, sadly, politics is often very important. There are things I need to discuss of a political nature where it is better that no evidence of the discussion remains.
lack of subtlety and emotion. Emoticons suck. I add smiley faces to tone down the harshness of some of my e-mails, but it is nothing like human speech. The written word is simply not as powerful as the spoken word.
These are more reasons for phoning someone mind, not for answering your phone. You might want to treat people as you wish to be treated yourself, but on the other hand business can be something of a dog eat dog world and often you may prefer to just look after your own selfish interests and to hell with the rest.
