Installed Google shortly it was announced on news.com. Immediately tested with some of the IT savvy friends and found that Google Talk voice quality is as good as Skype. One major different between Google Talk and Skype is the Skype has the Skype out feature that allow you to call any fixed line or mobile number at extremely economical rate.
Google Talk can be downloaded at http://www.google.com/talk/
As I used Gmail a lot these days, I found that using Google Talk and Gmail together extremely handy.