Talk 
Google Talk is an easy service you can use to make computer-to-computer calls, to send instant messages, to transfer files, and to leave voicemail messages for your friends. The downloadable application makes real-time communications simple and intuitive.
Features
- Real-time communication: Text chat
- Instant messages: share quick thoughts in real time
- Status updates: see if friends are online
- File transfer: instantly send and receive files, pictures, and more
- No Client Applications
- Integrated into Gmail InBox
- PC-to-PC audio chat anywhere in the world
- Audio conferencing: talk to multiple people at once
- Video chat
- High-quality video communication without launching a separate application.
- Integrated with Chat box and web cams.
