Skype 126.96.36.1995 - Voice-over-internet phone and chat software.. (Free): "
Skype allows you to talk to friends, family and co-workers across the internet without the inconvenience of long distance telephone charges. Using peer-to-peer data transmission technology, Skype eliminates the central server as a middle manager.
Today, millions of individuals and businesses are taking advantage of Skype's diverse communication features:
- Free Skype-to-Skype
- Landline and cellphone calling
- SMS and instant messaging
- Free video calls
- Call forwarding to your phone when you're offline
- bug fixes and stability improvements
Mac OS X 10.5.8 or later
(Via MacUpdate - Mac OS X.)