I hate using the phone, despite being a good communicator face-to-face. I particularly hate phoning people I don't know well (such as clients, unfortunately!). The advent of e-mail has been a godsend for me!

I think it comes down to not being able to see body language while I'm talking to someone. I can't tell how they're feeling, if they're annoyed to be disturbed, or just being polite, or whatever. Probably stems from my inner paranoia/lack of self esteem.