You know, for all that I don't like to be interrupted on the phone, if you have something really important and urgent to tell me, then you should definitely call me. Although my first reaction will sometimes be somewhat brusque, that'll turn around in a hurry if something is happening. Similarly, if you're calling to talk to Ian, that's ok by me - you're not interrupting me then :)
However, if you're calling just to say hello and to chat, well, if I'm not expecting your call or I'm busy, then I'm not necessarily going to react well.
Onto another topic, I don't know what's up with me today. I'm so very tired and I've been sleeping most of the day. I had set an alarm to wake me at about 10:30am... I remember half-waking up and thinking that someone's alarm was going off. I didn't wake fully up, though, and I didn't get up until after noon.