Y'know who bugs the crap out of me?
People who do not pick up on subtle, or sometimes not-so-subtle cues on the telephone. Especially on work related calls.
I'm a busy guy, and I assume that you are too. That's why when I talk to you, I'll usually ask you if this is a good time, or if I've caught you in the middle of something.
Its also why I try to pick up on subtle cues during the call. Are you talking to other people in the background about a problem with a server? Sound generally rushed and hurried? These are easy examples of cues that signal that this is a bad time for a long phone call.
If you have some information to share with me, great. If it takes you more than two or three minutes to share that information with me, we probably need to arrange a phone call, or you need to send me a long email.