Is there any, preferably free, VoIP (voice over IP) software that will allow me to talk to PC users? I have a friend, who is away for three months and she gets horrible cell phone reception and has no land line. I'm looking to use the Internet to talk to her instead. Does anyone have any recommendations? I don't believe iChat can do it and skype is for PC's only and I'd prefer to do it on my PowerBook. Thanks for any help or suggestions.