VOIP: Replacing your legacy phone system with Trixbox 2007: Google Talk Phone Calls, Offline Google Docs
More Cheap or Free VoIP/ Voice
Just a reminder that Jajah has free calls to 80 countries today, Christmas 2006. Vinay at VoIPGuides weblog also has several posts for free calling:
5 free VoIP providers for international calls (one of which is Jajah).
A hack for free calls through Free Call Planet.
MediaRing free calls from Dec 20 – Jan 6.