Ken Camp helps a regular reader out and explains that Google Talk isn't the only application that enables voice on the Nokia N800. Ken points out that GizmoProject, from the folks at SipPhone works on it too very well.
While GoogleTalk is resident out of the box on the N800, GizmoProject requires a quick download, but with it, you can make and receive real phone calls as well as talk with your GizmoProject buddies too.