If you are right-handed, put your phone on the LEFT side of the desk -- so you can hold the phone and take notes at the same time.
Don't feel compelled to ANSWER the phone every time it rings -- it's okay to let a call go to voice mail if you are working and don't want to be interrupted.
Let people know, on your answering machine, exactly when you will RETURN calls -- don't leave people hanging in "voice-mail limbo."
When leaving messages, use VOICE mail as a time-saving tool -- tell people exactly what you need, how to contact you, and the best time to reach you.
When leaving messages with a human being, ask that person to REPEAT your message back to you to make sure they got it right.
Ask if someone ELSE can help you, rather than leaving a message -- you may be taken care of quicker by another person.
Respect other people's time -- gather together all the information you need to take care of a request BEFORE you return a phone call.
Learn to use all of the FUNCTIONS on your phone -- call forwarding, do not disturb, conferencing -- to be as effective as possible at work.