Coccinella

Coccinella is an IM client that works with Jabber/Gtalk and includes a whiteboard where people can share ideas and exchange comments.

It includes a voice chat feature based on the VoIP protocol, allowing you to make phone calls and have conversations with several different users at the same time.

Coccinella gives you access to chatrooms with dozens of users, where you can quickly share files with each other. You can even use it with other IM services, such as AIM or MSN, although those services need to be configured through an external service.