Oh GOSH, phones!
I used to be a lot worse than I am, now. There was a time where it was virtually impossible for me to talk on the phone with anyone but my parents, and difficult even to talk to them. Over the years, I've gotten a little better about it... Now I have a select handful of friends and family members I can call comfortably (and even enjoy talking to), and I can at least pretend to be comfortable if someone else calls and I need to talk to them (like, say, for job interviews).
The fact that I have my own cell phone, now, helps. I avoided getting one for a long time, because I figured I would never use it because of my phone issues... but somehow having a full keypad for texting and the ability to set my ringtones to things that I can hear clearly without being startled by helps so much. Oh, and having control over who I give my number to-- everyone who calls my phone is calling ME, not my family members.
I also think online voice chats have helped me a bit-- those are a little cozier for me than talking on the phone, but they help me get more comfortable with disembodied voices.