VOIP + American "phone in" number

I am interested in connecting to a "phone in" workshop in the U.S. I live
in Australia. My doctor (who I didn't think was a computer buff) asked
"Why don't you use Skype?"

The idea had crossed my mind. There are alternatives to Skype, but my real
question is: does it work with the reverse-charge type of number?
Unfortunately I don't have the phone-in number available, but here we can
have 1300, for a trunk call which costs only a local call, and 1800, which
is completely free.

Doug.