It is no secret that Google supports Linux, considering that their two operating systems, Android and Chrome OS are both Linux-based, however they have always been a little slow in bringing their applications to the Linux platform. Google Earth was late to come for Linux, Picasa for Linux is too lags behind the Windows release, and SketchUp is just not available yet.
For those who have yet not tried it out, Google offers a plugin to enable voice and video chatting straight from your browser, using the chat functionality in GMail. However, up till now you needed to be running Windows or MacOS in order to make use of the plugin. GTalk itself is not available for Linux.