well this thread got me thinking, so I just got off the phone with telstra.
I pay 22 / month for line rental and usually make a maximum of 5 ph calls. the rest are via work funded mobile.
I told telstra I wanted to drop my phone line and keep my internet. They said I can keep my phone line, pay NO line rental, but they will increase my calls to 50c / local call (instead of 30c) and 50c/min for national and mobile.
SO i reckon thats a pretty good deal. no line rental, keep my traditional number, pay an extra 20c per ph call that i rarely make.