Be aware that if it is able to Skype will use your bandwidth to route other people's calls.
As i understand it the big ISPs in Australia have even more restrictive bandwidth quotas than ISPs over here are starting to introduce so, for your friend, using Skype could possibly exceed the quota.
If no one you're interested in talking to already has Skype it might be better to go with a different provider. I use
Gizmo which, like Skype, allows free calls PC-PC (and many other VOIP providers), a cheap local call-in number and the ability to call out to traditional land-lines.
Gizmo also uses open standards; SIP for voice, and Jabber/XMPP for Instant Messaging.
If you're just interested in talking PC-PC then one of the various IM services should suffice. I favour
Google Talk as it's based on the open Jabber/XMPP standards (which is what all IM services will use in the future). If you both have Gmail addresses you already have a Google Talk account.