Voice Chat on Linux

I am looking for a solution for Linux. Very lately I have realized the power of voice chat. I am frequently carrying out research discussions with my guide who is right now abroad and he is going to be there for a long time. Everytime he wishes to chat with me, I am forced to switch to an windows machine where gtalk is installed.

I tried my hands at Kopete, pidgin, ekiga, jabbin, gaim, psi etc. without much success. While text messaging is supported, I failed to configure voice chat on it. I know that voice chat is supported on skype. However, I don't want to create another account for it. Moreover I am google fan and won't like to switch over to skype so soon. I would keep updating this thread about the improvements I made in this regard.