Nimbuzz is a very popular IM client, as it supports Facebook, Yahoo, Windows Live, Google Talk, AIM, and others. In the past too, we have covered a tutorial on Nimbuzz SIP calls, that is how to configure Nimbuzz client to make SIP calls. Nimbuzz PC client is a great option for making SIP calls from PC.
With Microsoft taking over Skype and Fring also growing, it will be difficult for Nimbuzz to keep the growing rate. Nimbuzz writes on its blog "Our goal is to create a new experience for you so you can enjoy the best of both worlds. By doing this we hope to redefine the way users interact with their mobile social applications and pioneer a whole new app category".
It is really good to see that more and more people are switching to voip for making calls, rather free calls!